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SHIPS'     BOATS 

THEIR   QUALITIES,   CONSTRUCTION, 
EQUIPMENT,  AND  LAUNCHING 

APPLIANCES 


BY 


ERNEST    W.    BLOCKSIDGE,    M.Inst.N.A, 

MEMBER  SOC.    N.A«  AND  M.E. 

SHIP  SURVEYOR  TO  LI.OYl/S  REGISTER  OK  SHII'I'ING, 

FORMERLY  SHIP  SURVEYOR  TO  THE   MARINE    DEPARTMENT  OK  THE 

BOARD  OF  TRADE.    AND  LECTURER    ON    NAVAL   ARCHITECTURE 

TO  THE  DURHAM  HIGHER  EDUCATION  COMMITTEE 


iVlTH    DIAGRAMS    AND    ILLUSTRATIONS 


LONGMANS,    GREEN    AND    CO. 

39    PATERNOSTER    ROW,    LONDON 

FOURTH   AVENUE  &   30th    STREET.    NEW   YORK 
BOMBAY,   CALCUTTA,   AND   MADRAS 

1920 

All  rights  rrscrftd 


TO  THE 

SEAMEN  OF  THE  MERCHANT  MARINE 

This  treatise  is  dedicated  as  a  token  of  unqualified 
admiration  of  their  heroism,  self-sacrifice,  and 
splendid  achievements,  which  have  deservedly  gained 
the  highest  eulogies  of  the  civilised  world.  These 
pages  are  a  tribute  to  the  memory  of  those  who  were 
the  victims  of  a  treacherous  and  barbarous  enemy, 
and  written  with  the  hope  that  they  will  stimulate 
a  greater  interest  in  the  science  and  practical 
development  of  appliances  intended  to  secure  the 
full  measure  of  safety  for  those  who  voyage 
across  the  great  seas. 


VII 


PllEFACE 

Permission  was  given  the  Author,  during  the  period  of 
his  association  with  the  Marine  Department  of  the  Board 
of  Trade,  to  proceed  \\dth  the  publication  of  this  text-book ;  but 
in  fairness  to  the  officials  of.  that  Department  it  should  be 
stated  that  they  have  not  had  the  opportunity  to  express  an 
opinion  on  the  subject-matter  previous  to  publication,  owing 
to  professional  duties  taking  me  to  the  United  States  of 
America. 

All  matters  of  controversy  have  been  carefully  avoided ; 
the  sole  purpose  in  writing  the  treatise  being  to  circulate 
information  with  the  object  of  intensifying  the  interest  of  its 
readers  in  the  important  subject  of  the  ecjuipment  of  life- 
saving  appliances  on  cargo  and  passenger  vessels. 

Opportunity  is  now  taken  to  express  my  personal  apprecia- 
tion for  the  help  and  encouragement  given  me  by  my  former 
chiefs,  and  the  Committee  of  Lloyd's  Register,  during  the 
I)reparation  of  the  work. 

The  Author  wishes  to  acknowledge  his  indebtedness  to 
many  of  the  leading  -steamship  companies,  shipbuilders, 
engineers,  and  boatbuilders,  for  their  valuable  and  generous 
assistance ;  to  Mr.  W.  Mitchell,  Ship  Surveyor  to  the  Marine 
Department  of  the  Board  of  Trade,  (ilasgow,  for  his  co-opera- 
tion in  checking  the  manuscript ;  also  to  my  colleague  Mr  W. 
Bennett,  B  Sc,  MIN.A.,  Ship  Surveyor  to  Lloyd's  Register  of 
Shipping,  New  York,  for  reading  through  the  proofs,  and  for 
many  suggestions. 

E.  W.  BLOCKSIDGE. 

Wilmington, 

North  Carolina. 
1919. 


IX 


(From  JOHN  RUSKIN'S  "Hakboxiis  op  England.") 


Of  all  things,  living  or  lifeless,  upon  this  strange  earth,  there 
is  but  one  which,  having  reached  the  mid-term  of  apix)inted 
human  endurance  on  it,  I  still  regard  with  unmitigated 
amazement.  I  know,  indeed,  that  all  around  me  is  wonderful 
— but  I  cannot  answer  it  with  wonder ;  a  dark  veil,  with  the 
foolish  words,  Nature  of  Things,  upon  it,  casts  its  deadening 
folds  between  me  and  their  dazzling  strangeness.  Flowers 
open,  and  stars  rise,  &nd  it  seems  to  me  they  could  have  done 
no  less.  .  The  mystery  of  distant  mountain  blue  only  makes 
me  reflect  that  the  earth  is  of  necessity  mountainous;  the 
sea  wave  breaks  at  my  feet,  and  I  do  not  see  how  it  should 
have  remained  unbroken. 

But  one  object  there  is  still,  which  I  never  pass  without 
renewed  wonder  of  childhood,  and  that  is  the  bow  of  a  boat. 
Not  of  a  racing-wherry,  or  revenue  cutter,  or  clipper  yacht, 
but  the  blunt  head  of  a  common,  bluff,  undecked  sea-boat, 
lying  aside  in  its  furrow  of  beach  sand.  The  sum  of  Navi^^a- 
tion  is  in  that.  You  may  magnify  it  or  decorate  as  you  will, 
you  do  not  add  to  the  wonder  of  it.  Lengthen  it  with  complex 
tracery  of  ribs  of  oak— carve  it  and  gild  it  till  a  column  of 
light  moves  beneath  it  on  the  sea — you  have  made  no  more 
of  it  than  it  was  at  first.  That  rude  simplicity  of  bent  plank, 
that  can  breast  its  way  through  the  death  that  is  in  the  deep 
sea,  has  in  it  the  soul  of  shipping.  Beyond  this,  we  may 
have  more  work,  more  men,  more  money,  we  cannot  have 
more  miracle. 

For  there  is  first,  an  infinite  strangeness  in  the  perfection 
of  the  thing,  as  work  of  human  hands.  I  know  nothing  else 
that  man  does,  which  is  perfect,  but  that :  all  his  other  doings 


xl 


XII 


have  some  sign  of  weakness,  aflfectfction  or  ignorance  in  them. 
They  are  over-finished  or  under-finished;  they  do  not  quite 
answer  their  end,  or  they  show  a  mean  vanity  in  answering  it 
too  well. 

But  the  boat's  bow  is  naively  perfect;  complete  without 
an  effort.  The  man  who  made  it  knew  not  that  he  was 
making  anything  beautiful,  as  he  bent  its  planks  into  those 
mysterious,  ever-changing  curves.  It  grows  under  his  hand 
into  the  image  of  a  sea-shell;  the  seal,  as  it  were,  of  the 
flowing  of  the  great  tides  and  streams  of  ocean  stamped  on 
its  delicate  rounding.  He  leaves  it  when  all  is  done,  without 
a  boast.  It  is  simple  work,  but  it  will  keep  out  water,  and 
every  plank  thenceforward  is  a  Fate,  and  has  men's  lives 
wreathed  in  the  knots  of  it,' as  the  cloth -yard  shaft  had  their 
deaths  in  its  plumes. 


CONTENTS . 

PAET  I 

SCCriOK  l>AOR 

Introductory 1 

PAKT   II 

A.     Trades  of  vessels  as  affecting  boat  accommodation  and  the  installa- 
tion of  davits 4 

B      Classification  of  boats 20 

C.     Form,  stability,  strength,  and  capacity  of  boats      ......  28 

PART   III 

A.  Timber — conversion,  seasoning,  diseases,  selection,  strength,  etc.     .       84 

B.  Principal    woods    used    in    the    construction   of    boats,  and   their 

respective  qualities 97 

C.  Tlie  equipment  of  a  boat-yard 1()5 

PART   IV 

A.  Construction  of  Class  Ia  open  lifeboats 110 

B.  Construction  of  Class  Ib  open  lifeboats 195 

C.  Construction  of  Class  III.  boats ....  199 

D.  Construction  of  Class  IIa  open  lifeboats  with  collapsible  bulwarks  .  2(\0 

E.  Construction   of    Class   Ic,   IIb,    and    lie   pontoon    lifeboats   with 

collapsible  bulwarks 223 

PART   V 

A.  Motor  boats 235 

B.  Nested  boats 2GG 

C.  Surf  boats 273 

D.  Steel  boats 278 

PART   VI 

A.  Details  of  lifting  hooks,  keel  plates,  chain  slings,  etc 2S9 

B.  Boats*  engaging  and  disengaging  gear 311 

C.  Construction  of  buoyancy  air-cases 330 

xili 


xiv  CONTENTS 

PART  VII 

BKCTION  J'AOK 

A.  Equipment  of  boats 342 

B.  Sftils 357 

C.  Methods  of  galvanising 377 

D.  Painting 882 

K.    licpairs  and  maintenance  of  boats 380 

PART   VIII 

Fire  and  boat  drills 391 

PART    IX 

Weights  of  lifeboats,  equipment,  and  materials 399 

PART   X 

A.  Boat  stowage  and  transporting  arrangements 403 

B.  Roimd  bar  radial  davits 421 

C.  Patent  appliances  for  launching  ships*  boats 444 


APPENDIX 

A.  Instructions  for  the  construction  of  life-rafts 469 

B.  Instructions  for  the  construction  of  buoyant  apparatus    ....  473 

C.  Syllabus  for  technical  instruction  in  boatbuilding 479 

D.  Table  of  squares  and  cubes 482 

E.  Decimals  of  a  foot  for  each  ^^  of  an  inch        ....  488 

P.     Decimals  of  an  inch  for  each  ,}-^  of  an  inch 490 

G.    Approximate  freeboard  for  Class  I.  open  boats 490 

Index 491 


TABLES 

PART  II.— SECTION  A 

KClCRKn  PAOK 

I.  Minimum  number  of  set«  of  davits  and  open  boats  for  vessels 
in  Class  I.  Poreign-going,  or  Classes  I.  and  V.  Home  Trade, 
and  minimum  lifeboat  capacity 10 

II.    Minimum  lifeboat  capacity  for  vessels  in  Class  I.  or  Class  V. 

Home  Trade 14 

m.    Minimum  number  of  sets  of  davits  for  vessels  in  Class  V. 

Home  Trade,  in  certain  cases IG 

IV.     Minimum  lifeboat  capacity  for  vessels  in  Class  V.  Home 

Trade,  in  certain  cases 16 

V.     Minimum  number  of  sets  of  davits  for  vessels  in  Classes  VI. 

and  VII.  Home  Trade 17 

PART  II.— SECTION  0 

VI.     Minimum  breadths  to  inside  of  planking  at  half-midsbip  depth 

for  open  boats,  Classes  I.  and  III 35 

VII.     Dimensions  of  open  lifeboats,  Class  I.,  and  boat.'?  Clans  III., 

above  125  cubic  feet  capacity         .38 

VIII.     Dimensions  of  open  lifeboats,  Class  I.,  and  boats  Class  TIT., 

below  126  cubic  feet  capacity ...       30 

IX.     Dimensions  of  open  lifeboats,  Class   Ha,   and   pontoon   life- 
boats. Classes  IIb  and  He 40 

X.     Decimal  measurement  conversion  table 40 

XI.     Comparison  between  boats  of  various  Classes,  with  full  load        62 
XII.     Particulars  of  boats  A  and  C  under  stability  tests  (Report  of 

committee  on  boats  and  davits) 03 

PART  III -SECTION  A 

XIII.     Strength  and  elasticity  of  timber 90 

PART  IV.- SECTION  A 

XrV.     Scantlings  for  wooden  lifeboats,  Classes  Ia  and  Ib,  and  boats 

of  Class  III Ill 

XV 


xvi  TABLES 

NUMBER  PAGE 

XV.     Minimum  number  of  strakos  of   planking  in   clinker-built 

boats  6t  Classes  Ia,  Ib,  and  III 132 

XVI.    Particulars  of  copper  nails  and  roovcs 148 

XVII.     Approximate  number  of  copper  fastenings  in  a  26-ft.  lifeboat, 

Class  Ia 149 

XVIII.    Dimensions  of  thwart  knees,  etc.,  in  open  boats  of  Classes  I. 

and  III '    ....     170 

PART  VI.— SECTION  A 

XIX.     Scale  of  sizes  for  lifting  books  and  keel  plates  for  open  l)oat8 

of  Classes  I.  and  HI 29C 

XX.    Scale  of  sizes  for  keel  plates  of  Type  C  for  boats  20  feet  in 

length  and  under 301 

XXI.    Scale  of  sizes  for  keel  plates,  when  open  boats  of  Classes  I. 

and  III.  are  lifted  near  the  ends 803 

PART  VII.— SECTION  A 

XXII.     Particulars  of  thwarts,  crutches,  and  oars,  for  open  boats  of 

Classes  I.  and  III 347 

XXIII.  Distance  between  bottom  of  thwart  and  top  of  keelson  in 
open  boats  of  Classes  I.  and  III.  for  the  accommodation 
of  biscuit  cases 353 

• 

PART  VII.— SECTION  B 

XXIV.     Sail  areas  of  open  boats 366 

XXV.     Length  and  sizes  of  masts  for  open  boats  of  Classes  I.  and  III.   376 

PART  IX 

XXVI.     Weight  of  details  of  boats*  equipment 399 

XXVII.  Details  of  weights  of  lifeboats  (Classes  Ia  and  Lb)  .      .      .      .  400 

XXVIII.     Weights  of  materials 401 

XXIX.     Weights  of  persons 402 

PART  X.  -SECTION  B 

XXX.     Approximate  weight  and  strength  of  iiianiln  rope   ....     430 

XXXI.     Approximate  weight  and  strength  of  tibre-clad  hoisting  rope      432 

XXXIl.     Equivalent  sizes  for  hollow  and  Rulid  iron  davits    ....     441 


SHIPS'    BOATS 


PART  I 

INTRODUCTORY 

Many  valuable  books  dealing  with  the  design  and  construction 
of  ships  have  been  written  at  periodical  intervals  by  eminent 
Naval  Architects,  and  become  standard  works  of  reference  in  the 
libraries  of  our  Technical  Societies  and  Institutions.  Many 
questions  associated  with  the  theoretical  and  practical  aspects 
of  the  subject  have  been  thoroughly  investigated  and  published 
for  the  benefit  of  students  desiring  to  extend  their  knowledge  in 
the  Science.  The  sources  of  information  are  therefore  numerous 
and  varied. 

It  is  a  matter  of  some  surprise  that  the  important  subject 
of  the  equipment  of  cargo  and  passenger  vessels  with  life-saving 
appliances  has  never  been  dealt  with  in  detail  and  presented  as 
a  technical  volume  for  the  guidance  of  those  "  that  go  down  to 
the  sea  in  ships,  that  do  business  in  great  waters." 

Information  hitherto  has,  to  some  extent,  remained  sealed, 
not  from  any  desire  to  hinder  the  circulation  of  knowledge,  but 
due  mainly  to  the  fact  that  such  technical  literature  must 
necessarily  be  written  during  the  leisure  hours  of  a  practical 
man,  after  the  labours  of  the  day,  when  physically  and  mentally 
he  is  not  at  his  best. 

The  attention  of  the  whole  world  was  directed  to  the  terrible 
disasters  which  befell  the  large  passenger  steamers  TiUinic, 
Empress  of  Ireland,  Falaba,  Lusiixinia,  and  hundreds  of  other 
vessels  sunk  at  sight  by  the  unconstitutional  methods  of  an 
arrogant  enemy,  during  the  recent  war. 

The  subject  of  providing  the  best  apparatus  for  securing  the 
greatest  measure  of  safety  for  passengers  and  crew,  has  created 
widespread  interest  and  demanded  the  close  attention  of  the 
governing  authorities. 

B 


2  SHIPS'   B0AT8 

In  spite  of  many  difficulties,  tlie  writer  has  been  prompted 
to  bring  together  in  concrete  form  the  reaulta  of  some  measure 
of  practical  experience  a8sociat«d  with  the  methods  of  equipping 
merchant  vessels  with  life-saving  appliances. 

The  present  volume  is  mainly  devoted  to  the  subject  of  Boats ; 
their  construction,  stowage,  equipment,  and  launching  appliances. 
It  has  been  found  impossible  to  make  any  detailed  reference  to 
the  subject  of  life-rafts  and  buoyant  apparatus,  but  the  general 
instructions  relating  to  these  portions  of  the  life-saving  equipment 
have  been  inserted  in  the  Appendix. 

No  pretence  has  been  made  to  deal  with  abstruse  calculations, 
and  the  author  has  endeavoured  to  confine  himself  to  everyday 
language  in  explaining  the  various  methods  of  construction 
operating  in  the  boat  yards  and  engineering  works. 

A  feature  of  the  present  edition  is  the  large  number  of  illustra- 
tions, which  it  is  anticipated  will  prove  of  some  assistance  to 
Shipbuilders  and  Ships'  Officers,  wlio  have  little  opportunity  to 
secure  the  complete  information  in  suitable  form  for  reference. 

It  is  not  considered  out  of  place  to  give  a  brief  summary  of 
the  progress  of  legislation  which  insists  on  certain  requirements 
being  carried  out  on  all  merchant  vessels  for  the  safety  of 
passengers  and  crew. 

Previous  to  the  year  1890,  the  boat  accommodation  for  all 
British  ships  and  foreign  ships  canying  passengers  between  places 
in  the  United  Kingdom,  was  governed  by  Clause  292  of  the 
Merchant  Shipping  Act  of  1854,  and  based  on  the  veaael's  register- 
tonnage.  The  limit  for  a  vessel  of  1000  tons  and  upwards  was 
seven  boats,  provided  one  was  a  lifeboat,  in  the  case  of  a 
passenger  vessel.  Provision  was  not  made  for  additional  life- 
saving  appliances  beyond  the  supply  of  a  number  of  lifebuoys. 

In  March.  1886,  a  Departmental  Committee  was  appointed 
by  the  Board  of  Trade  to  inquire  into  the  question  of  boats, 
rafts,  and  life-saving  apparatus  carried  by  eea-going  merchant 
vesseb,  and  when  considering  the  equipment  of  passenger  steam 
vessels  carrying  large  numbers  of  emigrants  across  the  Atlantic, 
it  was  recommended  that  the  provision  under  the  statutory 
requirements  was  inadequate  and  that  each  ship  should  have 
sufficient  life-saving  apparatus  for  all  persons  on  board. 

As  a  result  of  the  recommendations  of  a  Select  Committee  of 
the  House  of  Commons,  presided  over  by  Lord  Charles  Beresford, 
in  the  year  1887,  Rules  for  Life-saving  Apphances  came  into 
operation  on  the  31st  March,  1890,  which  adopted  the  principle 
that  on  all  Foreign  and  Home  Trade  cargo  vessels,  the  boat 


INTRODUCTORY  3 

accommodation  should  be  sufficient  for  all  on  board,  and  that 
on  steamships  engaged  in  such  trades,  this  accommodation  should 
be  provided  in  boats  under  davits  on  each  side  of  the  vessel. 
These  rules  substituted  gross  for  register  tonnage  as  the  basis  of 
scale  for  the  equipment  of  emigrant  and  passenger  ships  up  to 
9000  tons  and  upwards ;  which  limit  was  again  increased  in 
1894  to  10,000  tons  and  upwards.  This  substitution  was  the 
means  of  increasing  the  boat  accommodation  in  steamships  by 
about  50  per  cent.  Provision  was  also  made  for  life-belts  and 
other  buoyant  apparatus  to  be  carried  for  all  persons  on  board. 

Further  rules  and  regulations  relating  to  life-saving  appliances 
were  introduced  at  various  periods  between  the  years  1902 
and  1914,  to  provide  for  the  adequate  equipment  of  vessels 
which  were  constantly  increasing  in  size  and  passenger  accommo- 
dation. 

After  the  regrettable  loss  of  the  s.s.  Titanic  in  the  Atlantic 
Ocean,  a  Merchant  Shipping  Advisory  Committee  was  appointed, 
followed  by  a  Departmental  Committee  on  Boats  and  Davits, 
and  the  International  Conference  for  the  Safety  of  Life  at  Sea. 

The  British  authorities  have  always  recognised  the  importance 
of  safeguarding  both  passengers  and  crew,  as  the  before-mentioned 
investigations  will  testify. 

The  Rules  for  Life-saving  AppUances,  issued  in  1914,  are  those 
which  now  govern  the  equipment  of  vessels.  Boat  accommo- 
dation and  the  number  of  davits  to  be  provided  depend,  not  on  a 
tonnage  scale,  but  on  the  registered  length  of  the  vessel. 

No  doubt  certain  modifications  and  additions  will  be  made 
in  the  future  as  a  result  of  the  experience  gained  during  the  recent 
war,  but  the  standard  of  the  present  requirements  are  of  a  very 
high  class. 

The  foreword  given  in  this  text-book  is  a  very  beautiful  and 
decorative  expression  of  an  author's  view  of  the  lines  and  form 
of  an  ordinary  open  boat.  The  practical  man  sometimes  finds, 
when  boats  are  constructed  under  certain  conditions,  that  beauty 
of  form  is  not  always  a  guarantee  that  "  it  will  keep  out  water." 
Experience  has  proved  the  necessity  for  regulating  the  con- 
struction of  ships'  boats  by  a  very  high  standard  of  workmanship, 
and  the  builders  are  now  guided  by  a  complete  and  com- 
prehensive specification. 

If  the  circulation  of  this  text-book  is  the  means  of  increasing 
the  interest  in  the  subject  of  the  equipment  of  our  merchant 
fleet  with  satisfactory  life-saving  appliances,  the  author  will  be 
gratified  with  the  result. 


PART  II 

SECTION  A.— TRADES  OF  VESSELS  AS  AFFECTING 
BOAT  ACCOMMODATION  AND  THE  INSTALLATION 
OF  DAVITS 

The  life-saving  equipment  of  our  Merchant  Fleet  is  governed  by 
the  nature  of  the  service  for  which  the  vessels  are  intended. 

The  requirements  of  Clause  427  of  the  British  Merchant 
Shipping  Act  of  1894  empower  the  Board  of  Trade  to  draw  up 
regulations  for  the  installation  of  life-saving  appliances  on  vessels, 
which  will  ensure  a  large  measure  of  safety  at  sea  for  the  passengers 
and  crew. 

From  time  to  time  the  Marine  Department  of  the  Board  of 
Trade  have  sought  the  advice,  experience,  and  co-operation  of 
influential  Committees  before  bringing  into  operation  their 
Regulations. 

The  recommendations  of  the  Departmental  Committee  on 
Boats  and  Davits,  and  the  results  of  the  investigations  made 
by  the  International  Conference  on  Safety  of  Life  at  Sea,  have 
now  been  embodied  in  the  latest  rules. 

For  the  purpose  of  drawing  up  Rules  for  Life-saving  Appliances 
the  vessels  have  been  classified  under  two  headings,  viz. — 
(1)  Foreign-going,  and  (2)  Honie  Trade.  Each  of  these  classes 
has  been  sub-divided  so  as  to  include  and  separately  identify  the 
various  vessels,  to  enable  the  equipment  to  suit  the  particular 
type  of  ship  or  trade  in  which  the  vessel  is  engaged. 

There  are  three  important  sections  of  the  Rules  for  Life-saving 
Appliances  which  exercise  a  controlling  influence  on  the  question 
of  equipping  a  vessel  with  the  regulation  number  of  boats  and 
sets  of  davits,  viz.  General  Rules  Nos.  2,  10  and  20. 

Portions  of  these  rules  which  affect  all  new  vessels  now  under 
construction  are,  therefore,  given  in  detail,  to  enable  the  reader 
to  familiarise  himself  with  the  modifications  which  may  become 
necessary  owing  to  the  special  features  of  the  ship's  design. 


TRADES  OF  VESSELS  AND  BOAT  ACCOMMODATION    5 

These  modifications    are  pemussible   under   certain  conditions, 
which  are  indicated  in  the  rules  and  are  as  follows  : — 


GENERAL   RULE    2    OF    THE   RULES    FOR   LIFE- 
SAVING    APPLIANCES. 

Power  of  the  Board  of  Trade  lo  accept  alternatives. 

"  The  Board  of  Trade  shall  have  power,  in  general  or  in  any 
'  particular  case,  to  accept  any  boat,  raft,  buoyant  apparatus, 
'  or  other  life-saving  appliance,  in  lieu  of  a  life-saving  appUance 
'  required    by  these  rules,  subject  to  such  conditions  as  they 

*  may  impose,  if  they  are  satisfied  that  under  those  conditions 
'  it  will  be  as  effective  as  the  appUance  required  by  these  rules. 

"  Provided  that  in  the  case  of  a  foreign-going  passenger 
'  steamer  no  life-saving  appUance  shall  be  accepted  in  Ueu  of  a 

*  lifeboat  required  by  these  rules,  except  either  some  other 
'  approved  type  of  lifeboat  or  a  life-raft  approved  as  being 
'  in  every  respect  as  efficient  as  the  pontoon  life-raft  described 
'  in  General  Rule  10. 

"  Provided  also  that  no  life-raft  shall  be  accepted  on  a  foreign- 

*  going  passenger  steamer  unless  the  total  cubic  capacity  of  the 
'  lifeboats  provided  is  at  least  equal  to  the  greater  of  the  two 
'  foUowing  amounts  :— 

"  (i.)  75  per  cent,  of  the  total  capacity  required  to 
"  accommodate  all  the  persons  carried. 
"  or  (u.)  The  minimum  capacity  required  by  Column  C  of 
"  the  Table  in  Appendix  I."    (See  p.  10.) 


GENERAL  RULE   10   OF   THE  RULES   FOR 
LIFE-SAVING  APPLIANCES. 

Life-rafts, 

**  (1)  An  approved  pontoon  life-raft  shall  satisfy  the  foUowing 
'*  conditions  : — 

(i.)  It  shall  be  reversible  and  fitted  with  bulwarks  of 

"  wood,  canvas,  or  other  suitable  material  on 

both      sides.      These      bulwarks      may      be 

collapsible. 

(ii.)  It  shall  be  of    such    size,  strength,    and    weight 

"  that  it  can  be  handled  without  mechanical 


SHIPS'  BOATS 


"  appliances,  and,  if  necessary,  be  thrown  from 
"  the  vessel's  deck. 


(iii.)  It  shall  have  not  less  than  three  cubic  feet  of 
air-cases   or   equivalent   buoyancy   for  each 
person  whom  it  can  accommodate, 
(iv.)  It  shall  have  a  deck  area  of  not  less  than  four 
square  feet  for   each   person   whom   it  can 
*'  accommodate  and  the  platform  shall  be  not 
"  less   than  six  inches   above  the   water  level 
"  when  the  raft  is  loaded. 
**  (v.)  The  air-cases  or  equivalent  buoyancy  should   be 
"  placed  as  near  as  possible  to  the  sides  of  the 
"  raft. 
"  (2)  Every  raft  shall  be  marked  to  the  satisfaction  of  the 
"  Board  of  Trade  in  such  a  way  as  plainly  to  indicate  the  number 
"  of  persons  for  which  it  is  approved. 

**  (3)  Two  children  under  the  age  of  twelve  may  be  carried  in 
place  of  one  adult  person. 

(4)  In  ships  which  carry  rafts  there  shall  be  a  sufficient 
number  of  rope  ladders,  or  other  approved  appliances,  always 
available  for  use  in  embarking  the  persons  in  the  rafts." 


PART  OF  GENERAL    RULE  20  OF  THE  RULES  FOR 

LIFE-SAVING  APPLIANCES. 

Exemptions. 

"  (1)  If  it  appears  to  the  Board  of  Trade,  on  the  application 
"  of  the  owner  of  any  ship,  that  it  is  not  practicable  or  reasonable 
"  to  fit  in  that  ship  the  number  of  sets  of  davits  required  by  these 
"  rules,  the  Board  may  direct  that  one  or  more  sets  of  davits 
"  may  be  dispensed  with  in  that  ship  subject  to  such  conditions, 
"  if  any,  as  the  Board  may  require. 

"  Provided  that,  in  the  case  of  a  foreign-going  passenger 
''  steamer,  the  number  of  davits  fitted  shall  not  be  less  than  the 
**  minimum  number  of  open  boats  of  Class  I.  required  by  these 
"  rules,  except  in  the  following  case  : — 

"  If  a  large  proportion  of  the  persons  on  board  are  accommo- 
''  dated  in  boate  whose  length  is  greater  than  50  feet,  a  further 
''  reduction  in  the  number  of  sets  of  davits  may  be  allowed  if  the 
'*  Board  of  Trade  are  satisfied  that  the  arrangements  are  in  all 
*'  respects  satisfactory.  .  .  . 


it 


TRADES  OF  VESSELS  AND  BOAT  ACCOMMODATION    7 

"  Provided  further  that,  in  the  case  of  a  foreign-going 
'  passenger  steamer,  the  owner  of  the  ship  in  question  shall  be 
'  required  to  prove,  by  a  test  made  in  the  presence  of  a  Board 
'  of  Trade  Surveyor,  that  all  the  boats  can  be  launched  in  a 
'  time,  to  be  fixed  by  the  Board  of  Trade.  The  conditions  of 
'  this  test  shall  be  as  follows  : — 

"  (i.)  The  ship  is  to  be  upright  and  in  smooth  water. 
"  (ii.)  The  time  is  the  time  required  from  the  beginning 
of  the  removal  of  the  boat  covers,  or  any 
other    operation   necessary    to    prepare    the 
"  boats  for  lowering,   until  the  last  boat,   or 
"  pontoon  raft,  is  afloat. 
"  (iii.)  The  number  of  men  employed  in  the  whole  opera- 
"  tion  must  not  exceed  the  total  number  of 
"  boat    hands    Ijhat    will    be    carried    on    the 
"  vessel  imder  normal  service  conditions, 
(iv.)  Each  boat  when  being  lowered  must  have  on 
board  at  least  two  men,  and  its  fuU  equipment 
as  required  by  these  rules." 
In  discussing  the  various  regulations  which  control  the  number 
of  boats  and  sets  of  davits  to  be  installed  on  ships,  each  type  of 
vessel  will  be  dealt  with  in  the  order  of  classification  and  under 
the  two  headings  of  '*  Foreign-going,"  and  "  Home  Trade." 

FOREIGN-GOING. 

Class  I. — Foreign-^oing  passenger  steamers,  includitig 

emigrarU  ships. 

The  registered  length  of  passenger  steamers  governs  the 
number  of  sets  of  davits  to  be  installed,  and  in  combination  with 
these  davits,  a  minimum  aggregate  cubic  capacity  for  the  lifeboats 
must  be  obtained. 

Lifeboats  must  be  carried  in  such  numbers  as  will  be 
sufficient  to  accommodate  the  total  number  of  persons  on  board, 
or  the  number  which  the  ship  is  certified  to  carry,  whichever  is 
the  greater. 

The  nimiber  of  sets  of  davits  to  be  fitted  to  a  ship  of  this 
class  must  be  in  accordance  with  Column  A  of  Table  I.,  p.  10. 

Each  set  of  davits  must  have  a  lifeboat  of  Class  I.  attached 
to  it ;  and  of  these  lifeboats,  at  least  the  minimum  specified  in 
Column  B  of  Table  I.  must  be  open  boats. 

The  aggregate  cubic  capacity  of  the  lifeboats  in  feet  must  not 
be  less  than  the  minimum  specified  in  Column  C  of  Table  I. 


SHIPS'  BOATS 

An  example  will  be  taken  to  explain  liow  tlieae  various  clause» 
operate  in  a  particular  vessel,  and  the  permissible  deviations 
which  may  be  made  with  the  sanction  of  the  Board  of  Trade, 
under  specified  conditions,  to  suit  the  design  of  vessel  and  the 
number  of  passeugei-s  carried. 

Consider  a  foreign-goiiiy  passenger  steamer  500  feet  in 
lengtli. 

The  minimum  number  of  scte  of  davits  required  to  be  fitted 
in  accordance  with  Table  I.  is  14^  and  the  minimum  number  of 
open  boats  of  Class  I.  which  must  be  attached  to  these  davits  b 
10.  This  leaver  four  boats  to  be  attached  to  the  remaining 
davits,  which  may  be  either  open  boat«  or  pontoon  boat«  of 
Class  I. ;  that  is  to  say,  all  boats  attached  to  davits  must  have 
rigid  sides  aud  not  collapsible  bulwarks. 

The  minimum  aggregate  capacity  of  tlie  lifeboats  taken  from 
Column  C  of  Table  I.  must  be  17,310  cubic  feet. 

The  maximum  size  of  a  Class  1a  lifeboat  for  the  vessel  taken 
as  an  example  would  be  28'0'x8'5' x3'5',  giving  a  capacity  of 
500  cubic  feet  and  accommodation  for  50  persons. 

Dividing  tlie  minimiun  aggregate  by  the  single  boat  capacity, 

i.e.   -  J^.-,  we  find  that  34  boats  are  required. 
oOO  ^ 

Fourteen  lifeboats  of  Class  I.  are  already  provided  and  attached 
to  davits.  Fourteen  boats  with  collapsible  bulwarks  could  be 
stowed  beneath  the  Class  1.  boats,  leaving  six  others  of  Class  I. 
or  Class  II.  to  be  stowed  inboard. 

The  provision  of  34  boal*i  of  the  stated  size  would  give  accom- 
modation for  about  1700  passengers. 

For  the  purpose  of  explaining  the  Lile-saving  Appliances 
Rules,  let  us  suppose  the  shipowner  wishes  t<)  carry  a  larger 
number  of  passengers,  say  2000.  Then  it  woidd  be  necessary  to 
provide  additional  lifeboats  to  accommodate  the  full  number  of 
persons. 

If  the  shipowner  wishes  to  claim  the  provisions  contained  in 
General  Rule  2  of  the  L.S.A.  Rules,  we  find  that  seventy-five 
per  cent,  of  the  boat  capacity  to  accommodat-e  2000  passengers, 
is  15,000  cubic  feet.  The  minimum  capacity  required  bv 
Column  C  in  Table  I.  is  17,310.  The  Board  of  Trade  may,  there- 
fore, consider,  in  this  case,  the  question  of  the  supply  of  approved 
life-rafts  in  lieu  of  the  lifeboats  required  by  the  rules,  to  make 
up  for  the  additional  number  of  passengers  carried. 

j\gain.  suppnsc  the  vessel  was  only  carrying  WKI  passi^ngera 
und  crow,  then  it  would  only  be  necessary  to  provide  ten  davibi 


TRADES  OF  VESSELS  AND  BOAT  ACCOMMODATION    9 

instead  of  fourteen,  when  treated  in  accordance  with  the  registered 
length. 

If  the  shipowner  or  shipbuilder  considers  that  it  is  not 
practicable  or  reasonable  to  fit  the  number  of  sets  of  davits 
required  by  the  rules,  then  special  application  must  be  made  to 
the  Board  of  Trade  for  permission  to  dispense  with  one  or  two 
sets.  The  conditions  imder  which  approval  is  granted  are  stated 
in  General  Rule  20  of  the  L.S.A.  Rules,  the  details  of  which  have 
already  been  given  and  are  self-explanatory. 

All  the  davits  of  passenger  vessels  must  be  of  such  a  design 
that  they  can  laimch  the  boat  from  its  stowing  position  and 
lower  it  safely  into  the  water,  the  ship  being  assmned  to  have 
a  list  of  15  degrees. 

If  the  master  or  owner  of  a  ship  of  this  class  claims  to  be 
carrying  on  a  voyage,  fewer  lifeboats  and  life-rafts  than  will  pro- 
vide suflScient  accommodation  for  all  persons  for  which  the  ship 
is  certified,  he  must  declare  before  the  collector  or  other  officer 
of  the  Customs,  before  the  time  of  clearance,  that  the  lifeboats 
and  life-rafts  actuallv  carried,  will  be  sufficient  to  accommodate 
all  persons  who  will  be  carried  at  any  time  during  the  voyage  to 
foreign  ports  and  the  voyage  back  to  the  United  Kingdom. 

Provision  is  also  made  in  the  Life-saving  Appliances  Rules 
by  the  Board  of  Trade  for  passenger  steamers  which  call  at 
certain  foreign  ports  during  the  voyage  from  or  to  the  United 
Kingdom  to  take  on  board  at  these  places  an  additional  number 
of  passengers,  within  the  terms  of  the  ship's  passenger  certificate. 
The  extra  boats,  davits,  or  other  life-saving  equipment  for  the 
additional  passengers  may  comply  with  the  rules  applicable  to 
the  class  of  Home  Trade  voyage  to  which  the  voyage  has  been 
scheduled  as  similar. 

This  clause  operates  in  quite  a  large  number  of  vessels  which 
leave  the  United  Kingdom  witli  passengers  for  various  ports  of 
call  on  the  voyage  to  China,  and  in  running  along  the  Chinese 
coast  a  large  number  of  emigrants  are  carried  between  the  different 
sections. 

The  two  following  notes  are  of  importance  : — 

Note  I, — All  open  lifeboats  carried  on  a  foreign-going  passenger 
steamer  must  be  fitted  with  buovancv  air-cases. 

Note  II. — In  arranging  the  boat  accommodation  for  foreign- 
going  vessels  which  are  certified  to  carry  not  more  than  twelve 
passengers,  reference  should  be  made  to  Section  C  of  Part  1 V.  in 
regard  to  the  provision  made  for  the  inclusion  of  Class  HI.  Boats 
in  the  statutory  equipment. 


10 


SfflPS'    BOATS 


TABLE  I. 

Appendix  /.  of  Ruhsfor  Life-saving  Appliances,  1914. 

MiKiMUBC  Number  of  Sets  of  Davits  and  the  Minimum  Number  of  Open 
Boats  required  to  be  provided  in  a  Steamship  in  Class  I.,  Foreign- 
QOiNO,  or  in  Class  I.,  Home  Trade,  or  in  Class  V.,  Home  Trade  (except 
in  certain  cases),  and  the  Minimum  Lifeboat  Capacity  for  the 
purposes  of  General  Rule  2. 


(A.) 

Registered  Length  of  the  Ship. 

Minimum 
number  of  sets 

of  davits. 

Feet.        Feet. 

100  and  under  120  .   .   . 

2 

120   „     140  . 

2 

140   ,.     160  . 

2 

160   „     175  . 

3 

175   .,     100  . 

3 

190   ..     205  . 

4 

205   „     220  . 

4 

220   .,     230  . 

5 

230   „     245  . 

245   „     255  . 

6 

255   „     270  . 

6 

270   ,.     285  . 

7 

285   „     300  . 

7 

300   „     315  . 

8 

315   „     330  . 

8 

330   „     350  . 

9 

360   „     370  . 

9 

370   .,     390  . 

10 

390   „     410  . 

10 

410   „     435  . 

12 

435   „     460  . 

i      12 

460   „     490  .   . 

i      14 

490   „     520  .   . 

14 

520   „     550  .   . 

16 

550   „     580  .   . 

16 

580    .,     610  .   . 

18 

610   „     640  .   . 

18 

640   „     670  .   . 

20 

670    ,     700  .   . 

20 

700   „     730  .   . 

22 

730   ,.     760  .   . 

22 

760   „     790  .   . 

24 

790   .,     820  .   . 

24 

820   ,.     855  .   . 

26 

856   „     890  .   . 

26 

890   „     925  .   . 

28 

92&   .,     960  .   . 

28 

960   ..     995  .   . 

30 

995   „    1030  .   . 

30 

(B.)  (C.) 

Minimum  Minimum  aggre- 

number  of  open  gate  cubic  capacity 

boats,  Class  I.  of  lifeboats  in  feet. 


2 

980 

2 

1,220 

2 

1,550 

3 

1,880 

3 

2,390 

4 

2.740 

4 

3,330 

4     i 

3.900 

4 

4,660 

5 

5.100 

5 

5,640 

5     1 

6.190 

5 

6,930 

6 

7,560 

6   .: 

8,290 

7 

9,000 

7 

9,630 

7' 

10,660 

7 

11,700 

9 

13,060 

9 

14,430 

10 

16,920 

10 

17,310 

12 

18,720 

12 

20,360 

13 

21,900 

13 

23,700 

14 

26,350 

14 

27,050 

15 

28,560 

15 

30,180 

17 

32,100 

17 

34,350 

18 

36,460 

18 

38,760 

19 

41,000 

19 

43,880 

20 

46,360 

20 

48,760 

\Mien  the  length  of  the  ship  exceeds  1,030  feet  the  Board  of  Trade  shall 
prescriba  the  minimum  number  of  sets  of  davits  and  the  minimum  number  of 
open  boats. 


TRADES  OF  VESSELS  AND  BOAT  ACCOMMODATION    11 

Class  II. — Foreign-going  steamships  not  certified  to  carry 
passengers : — 

Boat  accommodation  must  be  provided  on  each  side 
of  the  vessel  for  the  total  number  of  persons  carried  on 
board. 

The  inclusion  of  boats  without  buoyancy  air  -  cases 
in  the  statutory  equipment,  is  permissible  in  this  class  of 
vessel. 

If  the  total  number  of  lifeboats  required  exceeds  two,  a  boat 
of  Class  III.  may  be  carried  in  lieu  of  one  of  them  ;  and  if  the 
number  exceeds  three,  one  or  two  boats  of  Class  III.  may  be 
carried  in  lieu  of  the  same  number  of  lifeboats. 

Every  boat  which  forms  part  of  the  statutory  equipment  of  a 
vessel  must  be  attached  to  davits. 

Supposing  a  cargo  vessel  of  this  class  carries  a  crew  of  53,  in- 
cluding the  master,  then  one  lifeboat  of  Class  I  a,  240'  X  7*5'  X  30' 
with  seating  accommodation  for  32  persons,  and  one  boat  of 
Class  III.  200'x6"75'x2*6',  accommodating  21  persons,  stowed 
on  each  side  of  the  vessel  and  attached  to  davits,  would  be  a  con- 
venient arrangement  and  comply  with  the  regulations.  There 
would  therefore  be  boat  accommodation  for  106  persons,  under 
four  davits ;  and  for  this  reason  the  Rules  for  Life-saving  Ap- 
pliances do  not  insist  on  davits  being  fitted  with  mechanical 
arrangements  for  launching  the  boats  against  a  list. 

There  is  an  element  of  doubt  in  the  minds  of  some  ship- 
builders and  boatbuilders  as  to  whether  the  Class  III.  boats  carried 
on  a  cargo  steamer  are  required  to  be  equipped  with  the 
details  of  outfit  in  the  same  manner  as  the  Class  I.  lifeboats. 
The  whole  of  the  boats  carried  on  a  vessel  of  this  class,  if  they 
appear  on  the  Life-saving  Certificate  issued  by  the  Board  of 
Trade  Surveyor,  must  be  constructed  and  equipped  alike  in 
every  particular,  whether  they  are  Class  I.  or  Class  III.  with 
the  exception  that  Class  III.  boats  are  not  fitted  with  buoyancy 
tanks. 

The  United  States  Steamboat  Inspection  Service  previous  to 
June,  1919,  required  boat  accommodation  for  the  total  number  of 
persons  carri^  on  board,  cargo  and  passenger  steamers  being 
alike  in  this  respect,  but  since  that  date  instructions  have  been 
issued  that  in  the  case  of  ocean-going  cargo  steamers  suflicient 
boat  accommodation  must  be  provided  for  all  persons  on  board, 
on  each  side  of  the  ship,  thus  coming  into  line  with  the 
requirements  which  operate  in  Great  Britain. 


12  SHIPS'  BOATS 

Class  III. — Foreign-gaing  sailing  ships  carrying  more  than 
twelve  passengers : — 

A  vessel  of  this  class  must  carry  lifeboats  in  such  number 
and  aggregate  capacity  as  shall  be  sufficient  to  accommodate  all 
persons  on  board. 

All  the  lifeboats  must  be  attached  to  davits  so  far  as  practi- 
cable in  the  opinion  of  the  Board  of  Trade  Surveyor. 

The  position  of  the  davits  is  dependent  on  the  arrangements 
made  for  working  the  sails. 

Turning-out  gear  or  mechanical  davits  are  not  considered 
essential  for  vessels  of  this  class.  A  very  small  number  of  these 
vessels  are  now  in  actual  service. 

Class  IV. — Foreign-going  sailing  ships  not  carrying  more  than 
ttvelve  passengers : — 

A  ship  of  this  class  carries  a  lifeboat  or  lifeboats  of  Class  I., 
and  of  such  capacity  as  will  be  sufficient  to  accommodate  all 
the  persons  on  board. 

If  only  one  lifeboat  is  required,  an  additional  boat  of 
Class  III.  must  also  be  carried ;  and  if  the  total  number  of 
boats  required  exceeds  two,  then  a  boat  of  Class  III.  can  be 
carried  in  lieu  of  one  of  the  lifeboats. 

Two  boats  at  least  must  be  attached  to  davits,  one  on  each 
side  of  the  ship. 

The  provision  to  carry  boats  for  the  full  number  of  persons  on 
board,  on  each  side  of  the  ship,  which  appUes  to  cargo  steamers, 
does  not  operate  in  the  case  of  saiUng  vessels. 


HOME    TRADE. 

British  Hofne  Trade  Limits. — Between  places  in  the  British 
Isles  (the  United  Kingdom,  Channel  Isles,  and  the  Isle  of  Man), 
or  between  the  British  Isles  and  the  Continent  of  Europe,  between 
the  River  Elbe  and  Brest  inclusive. 

Class  l.~Steamships  certified  to  carry  passengers  anywhere 
within  Home  Trade  limits  : — 

In  vessels  of  this  class,  the  registered  length  comes  into 
operation  and  the  number  of  sets  of   davits  is  governed  by 


TRADES  OF  VESSELS  AND  BOAT  ACCOMMODATION    13 

Ck>lamn  A  of  Table  I.,  as  in  the  case  of  foreign-going  passenger 
vessels. 

Each  set  of  davits  must  have  a  lifeboat  attached 
to  it. 

The  lifeboats  attached  to  the  davits  may  be  either  open  or 
pontoon  lifeboats,  but  no  ship  shall  cany,  attached  to  davits, 
a  number  of  open  lifeboats  less  than  that  specified,  in  accordance 
with  its- length,  in  Column  B  of  Table  I.,  p.  10. 

If  the  specified  number  of  lifeboats  is  suflScient  to  accom- 
modate the  whole  of  the  passengers  and  crew  on  board,  it  is 
unnecessary  to  provide  a  number  of  sets  of  davits  greater  than 
the  number  of  boats. 

If  the  lifeboats  attached  to  davits  do  not  provide  suflScient 
accommodation  for  the  total  number  of  persons  carried,  or  which 
the  vessel  is  certified  to  carry,  whichever  number  is  the  greater, 
then  additional  lifeboats  must  be  carried  in  order  to  make  up 
the  total  capacity  as  specified  in  Table  II.,  p.  14. 

If  the  lifeboats  carried  in  accordance  with  the  regulations  are 
insuflSicient  to  provide  accommodation  for  the  total  number  of 
persons  which  the  ship  is  allowed  by  her  ordinary  passenger 
certificate  to  carry,  approved  life-rafts,  approved  buoyant  deck 
seats,  or  other  approv^  buoyant  apparatus  must  be  carried,  so 
that  these  additional  life-saving  appliances,  together  with  the 
specified  number  of  lifeboats,  provide  sufficient  accommodation 
for  the  total  number  of  persons  which  can  be  legitimately  carried 
on  board. 

Many  vessels  of  this  class  Are  given  a  special  certificate  when 
conveying  a  large  number  of  passengers  during  the  summer,  on 
daylight  voyages  between  the  20th  March  and  the  30th  September, 
inclusive.  To  make  adequate  provision  for  the  additional  number 
of  persons  carried  beyond  the  number  allowed  by  her  ordinary 
passenger  certificate,  the  lifeboats,  approved  life-rafts,  approved 
buoyant  deck  seats,  or  other  approved  buoyant  apparatus  carried 
on  board,  must  provide  sufficient  accommodation  for  80  per  cent. 
of  the  number  allowed  by  the  special  passenger  steamer's  certifi- 
cate, but  in  no  case  must  the  total  accommodation  provided  by 
the  life-saving  appliances  be  less  than  that  which  is  sufficient  for 
the  number  of  persons  allowed  by  the  ordinary  passenger 
certificate. 


14 


SHIPS'   BOATS 


TABLE  IL 

Appendix  IL  of  Rules  for  Life-saving  Appliances  (1914). 

Minimum  AaoBEGiiTE  Cubic  Capacity  op  Lifeboats  to  be  carried  in  a  Ship 
IN  Class  I.,  Home  Trade,  launched  on  or  after  the  1st  March,  1913, 
OR  IN  Class  V.,  Home  Trade,  launched  after  that  date  (except  in 
certain  cases). 


Length  of  vesael  in  feet. 


Minimum  aggregate  capacity 
of  lifebofits,  in  cubic  feet. 


100  and  under  120 
120    „    140 
)40    „    160 

160 
176 
190 

It 
«» 

11 

175 
190 
205 

205 
220 
245 

»» 
»» 

220 

245 

•270 

270 
300 

300 
330 

330 

tf 

370 

370 
410 

410 
460 

400 
600 
850 

1150 
1300 
1450 

1600 
1850 
2350 

3000 
3750 

4400 

5100 
6000 


In  the  case  of  a  vessel  of  under  100  feet,  or  over  460  feet,  the  cubic  capacity 
of  the  lifeboats  to  be  carried  shall  be  prescribed  by  the  Board  of  Trade. 


Class  IL — Steamships  trading  within  Home  Trade  limits,  hut 
ryot  certified  to  carry  passengers : — 

Vessels  of  this  class  when  100  feet  in  length  and  over,  must 
carry  a  boat  or  boats  on  each  side  of  the  ship  of  such  capacity  as 
shall  be  sufficient  to  accommodate  all  persons  on  board.  One 
of  the  boats  may  be  of  Class  III.,  but  the  remainder  must  be  of 
Class  I. 

All  the  boats  must  be  attached  to  davits. 
^  Vessels  under  100  feet  in  length  must  carry  one  lifeboat  of 
Class  I.  of  sufficient  capacity  to  accommodate  all  persons  on 
board,  and  stowed  in  such  a  manner  that  it  can  be  readily  launched 
on  either  side  of  the  ship.  It  is,  therefore,  not  compulsory  to 
fit  davits  in  these  vessels,  and  the  usual  procedure  is  to  utilize 
the  derrick  from  the*  main  mast  as  shown  in  Fig.  237. 


TRADES  OF  VESSELS  AND  BOAT  ACCOMMODATION    15 

Class  IIL — Sailing  ships  carrying  passengers  anywhere  within 
Home  Trade  limits : — 

A  ship  of  this  class  must  be  provided  vrith  a  lifeboat  or  life- 
boats of  such  capacity  as  will  be  sufficient  to  accommodate  the 
total  number  of  persons  on  board. 

The  boats  are  attached  to  davits  as  far  as  practicable. 

In  sailing  vessels  there  is  always  the  difficulty  of  the  davits 
interfering  with  the  proper  working  of  the  sails,  and  each  case 
must  therefore  be  dealt  with  when  considering  the  particular 
rigging  arrangements  fitted  to  the  vessel. 

Class  IV. — Sailing  vessels  trading  within  Home  Trade  limits,  hit 
not  carrying  passengers : — 

Provision  must  be  made  for  a  boat  or  boats  of  such  capacity 
as  will  be  sufficient  to  accommodate  all  persons  on  board.  At 
least  one  of  the  boats  must  be  an  open  boat  of  Class  I.  The 
boats  are  stowed  so  that  they  can  readily  be  placed  in  the  water 
on  either  side  of  the  ship.  It  is  not  always  possible  to  attach  the 
boats  to  the  davits  owing  to  the  restricted  space  for  working  the 
sails. 

A  concession  is  made  in  the  case  of  a  vessel  of  this  class  if 
under  100  feet  in  length ;  the  boat  or  boats  carried  may  be  of 
Class  III. 

Class  V. — Steamships  certified  to  carry  passengers  on  short 
specified  passages  along  the  coasts  of  the  United  Kingdom^  or  between 
Great  Britain  and  Ireland,  or  between  Great  Britain  or  Ireland  and 
the  Isle  of  Man. 

The  same  regulations  which  govern  the  boat  accommodation 
and  davit  equipment  of  vessels  of  Class  I.  of  the  Home  Trade,  also 
operate  in  the  case  of  vessels  of  Class  V.  and  in  addition  a  special 
provision  is  made  when— 

(a)  A  ship  of  this  class  is  engaged  near  the  coasts  of  the 
United  Kingdom,  specially  scheduled  by  the  Board  of  Trade  for 
this  purpose,  or — 

(6)  When  engaged  on  dayUght  excursions,  specially  scheduled 
by  the  Board  of  Trade  for  this  purpose,  between  the  1st  June  and 
the  31st  August,  inclusive. 

In  each  of  these  cases  the  vessels  are  not  required  to  carry 
more  sets  of  davits,  or  lifeboats  of  a  greater  aggregate  cubic 
capacity,  than  are  respectively  specified  in  the  second  columns  of 
Tables  III.  and'lV.  on  p.  16. 


16 


SmPS'   BOATS 


TABLE  III. 

Appendix  III.  of  Rules  for  Life-saving  Appliances  (1914). 

Minimum  Number  of  Sets  of  Davits  required  to  be  provided  in  a  Steam* 

SHIP  in  Class  V.,  Home  Trade,  in  certain  cases. 


Length  of  steami^hlp  in  feet. 

1    Bf  inimura  number  of  sots  of 
1                    (lavita. 

1 

Under  180 

2 

180  and  under  210      .      .      . 

3 

210 

240       ... 

4 

240          „ 

270       ... 

T) 

270 

300       ..      . 

(> 

300 

330       ... 

7 

330 

3(K)       .      .      .      . 

8 

In  the  caac  of  a  stoamBhip  of  over  360  feet,  the  number  of  sets  of  davits  to 
be  provided  shall  be  prescribed  by  the  Board  of  Trade. 

TABLE  IV. 

Minimum  Aggregate  Cubic  Capacity  of  Lifeboats  to  be  carried  in  a 
Steamship  in  C^ass  V.,  Home  Trade,  launched  on  or  after  the  1st 
March,  1913,  in  certain  cases. 


T^nffth  nf  atfliinmhin  in  f^flt           '  Minimum  aggregate  capacity 
Lengtn  or  steamship  in  feet.               ^^  lifeboats  in  cubic  feet. 

100  and  under  120       . 

.      .      .   ,                        300 

120           .,         140 

4<M) 

140         „        im 

500 

UA)          „         180 

<J00 

1 

ISO           .,         195 

700 

195           „         210 

8(H) 

210           „         225 

950 

225           „         240 

1,080 

240           „         255 

,                      1,250 

255           „         270 

1,460 

270           „         285 

1,700 

285           „         300 

1,1HK) 

300           „         330 

2,150 

330           „         3(iO 

2,400 

In  the  case  of  a  steamship  of  under  100,  or  over  3(K)  feet,  the  cubic  capacity 
of  the  lifeboats  to  be  carried  shall  be  prescribed  by  the  Board  of  Trade. 

Class  VI. — Steamships  certified  to  carry  passengers  on  short 
excursions  to  sea,  i.e.  beyond  partially  smooth  uxiter  limits,  between 
\st  April  and  31st  October  inclusive,  during  daylight,  and  in  fine 
weather. 

The  registered  length  of  vessel  governs  tlie  number  of  sets  of 


TRADES  OF  VESSELS  AND  BOAT  ACCOMMODATION    17 

davits  to  be  provided  and   which   are  specified  in   Table  V. 
(see  below). 

Eachsetof  davits  must  have  a  lifeboat  of  Class  I.  attached  to  it. 

This  class  of  vessel  is  also  subjected  to  the  provisions  of 
General  Rule  20  (1)  of  the  Life-saving  Appliances  Rules,  a  copy 
of  which  will  be  found  on  p.  6. 

The  number  of  sets  of  davits  need  not  exceed  the  number  of 
boats  required  to  accommodate  the  total  number  of  persons 
carried,  or  which  the  ship  is  certified  to  carry,  whichever  number 
is  the  greater. 

The  lifeboats  must  be  of  reasonable  capacity,  having  regard 
to  the  size  and  design  of  vessel.  The  boat  arrangement  must 
receive  the  approval  of  the  Board  of  Trade. 

The  aggregate  capacity  of  4he  lifeboats  need  not  be  greater 
than  is  required  to  accommodate  the  total  number  of  persons 
which  the  ship  is  certified  to  carry. 

If  the  regulation  number  of  boats  is  insuflScient  to  accommo- 
date the  total  number  of  persons  carried  on  board,  or  certified  to 
be  carried,  then  additional  lifeboats  or  approved  life-rafts,  ap- 
proved buoyant  deck-seats,  or  other  approved  buoyant  apparatus 
must  be  provided,  as  shall  be  suflicient,  together  with  the  life- 
boats already  provided  in  accordance  with  Table  V.,  for  70  per 
cent,  of  the  total  number  of  persons  for  which  the  ship  is  certified. 

Class  vn. — Steamships  certified  to  carry  passengers  in  partially 
smooth  waters. 

The  same  regulations  govern  the  life-saving  equipment  of 
vessels  of  this  class  as  in  vessels  of  Class  VI.,  except  that  the 
percentage  for  provision  of  lifeboats,  life-rafts,  etc.,  is  60  instead 
of  70. 

TABLE   V. 

Appendix  IV.  of  Jiules  for  Life-saving  Applinncts  (1914). 

Minimum  Number  of  Sets  of  Davits  required  to  be  provided  in  a  »Steam- 

SHiP  OF  Class  VI.  or  Class  VII.,  Home  Trade. 

Length  of  8teain«Jup  iu  feet.  Mininmm  number  of  HeU  of 


Under  200 2 

200  and  under  240       ....  3 

240  „         280       ...      .  4 

280  „         320       ...      .  6 


In  the  case  of  a  steamship  of  over  320  feet,  the  number  of  sets  of  davits  to 
be  provided  shall  be  prescribed  by  the  Board  of  Trade. 

C 


18  SHIPS'   BOATS 

Class  Vlli. — Steamships  certified  to  carry  passengers  in  smooth 
waters  in  estuaries  and  lakes, 

A  ship  of  this  class,  if  not  under  70  feet  but  under  150  feet 
in  length,  must  cany  at  least  one  boat ;  and  if  150  feet  or  more 
in  length,  at  least  two  boats. 

The  boats  must  be  attached  to  davits. 

Including  the  before-mentioned  boat  or  boats  the  vessel  must 
also  carry  such  boats,  approved  life-rafts,  approved  buoyant 
deck-seats,  or  other  approved  buoyant  apparatus,  as  shall  be 
sufficient  to  accommodate  40  per  cent,  of  the  total  number  of 
persons  for  which  the  ship  is  certified. 

It  will  be  noticed  that  no  particular  class  of  boat  is  specified, 
and  invariably  an  ordinary  boat  or  boats  without  buoyancy 
air-cases  (Class  III.)  are  suppliedfand  fitted  under  davits. 

There  may  be  particular  cases  where  the  arrangements  on 
the  upper  deck  are  such  as  to  make  it  impracticable  to  carry 
out  the  statutory  requirements ;  consequently,  the  Board  of 
Trade  may,  in  their  discretion,  relieve  a  ship  of  this  class  wholly 
or  partially  from  the  operation  of  the  rules. 

Class  IX. — Steamships  certified  to  carry  passengers  in  smooth 
water  on  rivers  or  canals, 

A  ship  of  this  class,  if  not  under  70  feet  in  length,  shall  carry 
a  boat  in  such  a  position  that  it  can  readily  be  placed  in  the 
water.  In  addition  to  this  boat,  the  vessel  must  carry  such 
boats,  approved  Hfe-rafts,  approved  buoyant  deck-seats,  or 
other  approved  buoyant  apparatus,  as  shall  be  sufficient  to 
accommodate  40  per  cent,  of  the  total  number  of  persons  for 
which  the  ship  is  certified. 

A  vessel  less  than  70  feet  length  must  carry  boats,  approved 
buoyant  apparatus,  etc.,  for  40  per  cent,  of  the  total  number  of 
persons  certified  to  be  carried  ;  but  here,  again,  the  particulars 
of  the  vessel's  deck  arrangements  have  to  be  specially  considered 
and  the  matter  must  be  submitted  to  the  Board  of  Trade,  who 
may  in  their  discretion  relieve  the  ship  of  some  of  these  obligatory 
provisions. 

Class  X. — Steam  launches  and  motor  boats  certified  to  carry 
passengers  for  short  distances  to  sea. 

A  ship  of  this  class,  if  over  60  feet  in  length,  must  comply  with 
the  same  regulations  which  govern  vessels  of  similar  length  in 


I 


Class  VIII.  of  the  Home  Trade,  Vessels  of  60  feet  in  length  and 
under  are  not  required  to  carry  boats,  but  must  be  provided  with 
two  lifebuoys,  and  an  approved  life-jacket  for  each  person  and 
child  on  board.  These  provisions  are  considered  sufficient  to 
cover  all  reasonable  circumstances. 

Class  XL — Sailing  boats  carrying  tnore  tlum  twelve  passengers 
for  short  distances  to  sea. 

A  ship  of  this  class,  if  over  60  feet  in  length,  must  comply  with 
njis  regulating  the  life-saving  equipment  of  vessels  iu  Class  111, 
of  the  Home  Trade. 

If  the  vessel  is  GO  feet  or  under  in  length,  two  lifebuoys  nmst 
be  provided,  and  an  approved  life-jacket  for  each  person  and 
child  carried  on  board.     These  provisions  are  in  lieu  of  a  boat. 


Class  XU. — Steam  fish  carriers,  tvgs,  steam,  lighters,  dredgers, 
ateam  hoppers,  hulks,  and  barges,  which  proceed  to  sea. 

A  ship  of  this  class  shall  comply  with  the  rules  in  Class  II.  of 
the  Home  Trade. 

Vessels  which  are  towed  from  one  port  to  another,  say  from 
Belfast  to  Glasgow,  for  tie  purpose  of  having  their  machinery 
installe<l,  come  within  the  operation  of  these  rules  for  life-saving 
equipment,-  and  are  considered  for  the  time  heini^  as  hulks  which 
proceed  to  sen. 

Class  XIII. — iSleam  fi^sh  carriers,  lugs,  steam  lighters,  dredgers 
steam  hoppers,  htdks,  and  barges,  which  do  not  proceed  to  sea. 

A  ship  of  this  class  must  carry  a  boat  sufficient  to  accommodate 
all  persons  on  board. 

•  General  Remarks. — The  foregoing  quotations  are  based  upon 
the  regulations  contained  in  the  Rules  for  Life-saving  Appliances 
of  1914,  and  apply  to  new  vessels,  and  vessels  under  construction 
since  that  date.  Various  deviations  had  to  be  made  from  these 
rules  to  suit  the  retjuiiements  of  vessels  whose  keels  were  laid 
before  certain  spctritied  dates,  but  reference  has  not  been  made 

I  in  this  section  to  such  vessels. 
The  writer  has  endeavoured  to  use  the  language  of  the  rules, 
with  exphuiatory  notes  to  assist  the  reader  to  clearly  understand 
the  varied — and  often  confusing — requirements  which  must  be 
carefully    considered    when    preparing    the    arrangements    for 


SmPS'  BOATS 

accoiiiniocUtiHg  the  boats  and  mstalling  the  davits.  ]t  is  an 
advantage  to  the  shipbuilder  to  always  submit  plans  for 
the  consideration  of  the  Board  of  Trade  at  the  earliest  possible 
date. 

Each  country  must  draw  up  its  own  classification  of  vessels 
to  suit  the  local  conditions,  but  the  principles  approved  by  the 
International  Conference  on  Safety  of  Life  at  Sea  are  now  being 
practicallv  adhered  to  by  most  of  the  representative  nations. 

The  regulations  issued  by  the  Board  of  Supervising  Inspectora 
of  the  United  States  of  America,  are  divided  into  four  parte,  viz, 
(1)  ocean  and  coastwise ;  (2)  great  lakes  ;  (3)  lakes  other  than 
the  great  lakes,  bays,  and  sounds;  and  (4)  rivers. 

It  should  be  remembered  that  any  boat  which  forms  part  of 
the  statutory  ecjuipmeut  of  a  British  vessel,  must  not  be  less  than 
125  cubic  feet  in  capacity. 

Where  it  is  found  impossible  in  a  small  vessel  to  provide 
proper  facilities  for  stowing  and  handling  a  boat  of  this  capacity, 
then  appUcation  must  be  made  to  the  Board  of  Trade,  who  may, 
in  their  discretion,  allow  a  boat  of  smaller  capacity  to  be  carried 
,  on  the  vessel,  provided  it  is  large  enough  to  accommodate  all 
persons  carried  on  board. 

This  is  a  question  which  must  be  left  to  the  practical  experience 
of  the  surveyor  who  is  dealing  with  the  vosBel.  Each  individual 
case  is  dealt  with  on  its  merits,  for  it  is  obvious  in  the  ease 
of  small  coasting,  sailing,  or  auxiharj'  motor  vesseb,  that  it  is  very 
difficult  to  carry  out  the  statutory  requirements  in  their  entirety. 

In  the  United  States  of  America  the  Uraiting  size  for  ocean  and 
coastwise  vessels  is  180  cub.  ft.,  except  in  certain  classes  of 
vesseb  under  1000  tons  gross,  a  reduction  is  made  to  125  cub. 
ft.,  and  again  where  certain  steamers  of  400  tons  gross  and  under, 
operating  within  5  miles  of  land  and  there  is  lack  of  space  to 
properly  carry  a  boat  of  125  cub,  ft.,  permission  is  given  for 
a  boat  of  smaller  size,  but  it  must  be  large  enough  and  of  suitable 
character  to  carry  every  person  on  board. 


SECTION  B.—CLASSU-'l CATION  OF  BOATS. 

Ships'  boats  vary  m  type  and  design  ;  but  for  the  purpose  of 
appropriating  a  particular  type  of  boat  to  suit  the  requiremeutw 
of  each  class  of  vessel;  they  are  divided  into  two  main  groups,  viz. 
"  Opeji "  boats  and  "  Pontoon  "  boats. 

To  simplify  the  administration  of  the  Rules  for  Life-saving 


CLASSIFICATION   OF   BOATS  21 

Appliances,  the  two  main  groups  are  split  up  into  three  distinct 
classes,  viz. — 

Class  I.       Lifeboats,  with  rigid  sides. 

Class  II.      Lifeboats,  with  collapsible  bulwarks. 

Class  III.     Open  boats,  without  buoyancy  air-cases. 

To  enable  boats  to  be  carried  on  board  appropriate  to  the 
individual  design  and  trade  of  each  vessel,  the  three  principal 
classes  are  sub-divided  as  follows  : — 

Class  Ia. — Open  lifeboats  with  internal  buoyancy  only. 

This  type  of  boat  may  be  constructed  of  a  single  or  double 
thickness  of  wood,  or  a  single  thickness  of  metal. 

The  internal  buoyancy  is  provided  by  watertight  air-cases  or 
tanks,  fitted  along  the  sides  or  at  the  ends,  but  not  in  the  bottom 
of  the  boat.  The  ideal  position  for  the  buoyancy  tanks  would 
be  to  fit  them  to  the  height  of  the  gunwale  and  winged  out  as 
far  from  the  middle  line  as  the  internal  arrangements  of  the  boat 
will  allow. 

The  usual  practice  is  to  fit  them  under  the  thwarts  and  side 
seats,  the  tanks  lying  close  into  the  form  of  the  bilge ;  conse- 
quently, in  this  position  the  tanks  are  not  of  much  material 
advantage  towards  securing  a  self-righting  boat.  The  main 
object  in  fitting  the  air-tanks  is  to  provide  a  reserve  of  buoyancy 
should  the  boat  become  flooded.  It  is  a  matter  of  great 
difficulty  to  right  an  upturned  lifeboat  in  the  water,  with  the 
buoyancy  tanks  fitted  in  the  present  position,  and  it  is  con- 
sidered that  the  design  of  the  Class  Ia  lifeboat  can  be  improved 
and  made  of  more  practical  value,  if  the  tanks  are  placed  as  already 
suggested,  and  good  powerful  hand  pumps  fitted  at  each  end  of 
the  boat. 

A  section  of  the  Class  I  a  lifeboat  is  shown  in  Fig.  1,  and  a 
half  section  or  isometric  projection  is  given  in  Fig.  87,  which 
illustrates  the  general  lines  pf  construction  of  a  wooden  boat. 

The  material  of  the  internal  buoyancy  tanks  is  of  copper  or 
yellow  metal  of  not  less  than  18  ozs.  to  the  superficial  foot,  or  of 
other  durable  material.  Galvanised  iron  or  steel  has  proved 
to  be  most  unmiitable  for  the  purpose. 

In  the  case  of  a  wooden  boat,  the  internal  buoyancy  must  be 
at  least  equal  to  one-tenth  of  the  cubic  capacity  of  the  boat.  For 
example,  if  a  lifeboat  of  this  class  possessed  an  internal  capacity 
of  500  cub.  ft.,  but  was  only  certified  for  48  persons,  due  to 


22 


SfflPS'   BOATS 


insufficient  seating  accommodation,  it  would  still  be  necessary 
to  provide  50  cubic  feet  of  air-cases. 

In  the  case  of  a  metal  boat,  an  addition  is  made  to  the 
cubic  capacity  of  the  airtight  compartments  or  cases,  so  as  to 
give  it  buoyancy  equal  to  that  of  a  wooden  boat.  Reference 
should  be  made  to  Part  VI.,  Section  C,  for  a  description  of  the 
method  of  obtaining  the  amoimt  of  capacity  of  air-tanks  in  steel 
boats. 

The  number  of  persons  which  a  lifeboat  of  this  class  is  con- 
sidered fit  to  carry,  is  obtained  by  dividing  the  capacity  of  the 
boat  in  cubic  feet  by  the  standard  imit  of  capacity  of  10  cubic 
feet. 

If  a  lifeboat  of  Class  Ia  has  a  capacity  of  500  cub.  ft.> 
measured  by  Stirling's  rule,  the  number  of  persons  assigned 


L.W.L 


1' . 

1 

THWARTS 

' 

r— 1 'l||^ 

1 

AIR 

^'^            11 

|\    CASES 

y  __.. 

% 

LOWER 

• 

■  i 

CROSS  SEATS 

1 

1 

J 

Fig.  1. — ^Midship  section  of  Class  Ia  open  lifeboat. 

would  be  fifty,  provided  they  could  be  properly  seated  without 
hindrance  to  the  oarsmen. 

The  usual  form  of  an  open  lifeboat  of  Class  Ia  is  double  bowed, 
but  it  may  have  a  square  stem.  The  shape  of  the  ends  has  no 
influence  on  the  class. 

The  Class  I  a  lifeboat  is  considered  to  be  the  highest  standard 
of  efficiency  in  comparison  with  other  types. 


Class  Ib  — O'pen  lifeboats  mth  internal  and  external  buoyancy. 

The  details  of  construction  and  outline  of  form  of  this  type  of 
lifeboat  is  similar  in  all  respects  to  that  of  a  lifeboat  of  Class  Ia, 
except  that  external  buoyancy  is  fitted  in  addition  to  internal 
buoyancy. 

The  internal  buoyancy  of  wooden  boats  is  made  up  with 
waterrignt  air-cases  of  copper  or  yellow  metal,  the  total  volume 


CLASSIFICATION  OF    BOATS 


23 


of  which  is  equal  to  7J  per  cent,  of  the  cubic  capacity  of  the 
boat. 

The  material  used  to  form  the  outside  buoyancy  is  usually 
solid  cork,  attached  to  the  sides  of  the  boat  in  the  manner  de- 
scribed in  Section  B  of  Part  IV. 

The  volume  of  external  buoyancy,  if  of  solid  cork,  for  a  wooden 
boat,  is  not  less  than  thirty-three  thousandths  of  the  cubic 
capacity  of  the  boat. 

The  divisor  or  standard  imit  of  capacity  used  in  obtaining  the 
number  of  persons  which  this  class  of  lifeboat  Ls  considered  fit 
to  carry,  is  nine  cubic  feet. 

If  the  internal  capacity  of   a  lifeboat  is  500  cub.  ft.,  the 

500 
number  of  persons  allotted  would  be  ^—  =  55,  as  compared  with 

50  for  a  Class  Ia  lifeboat  of  the  same  dimensions. 


OUTSIDC 
OOYANCY 


Fio.  2. — Midship  section  of  Class  Ib  open  lifeboat. 

The  amount  of  internal  buoyancy  would  be  7|  per  cent,  of 
500  =  7*5  X  5  =  37*5  cub.  ft.  of  watertight  air-cases. 

The  amount  of  external  buoyancy,  if  of  solid  cork,  is  therefore 

33 
500  X-^— ^=  16*5  cub.  ft.,  making  a  total  buoyancy  of  54  cub. 

ft.,  being  an  addition  of  4  cub.  ft.  as  compared  with  that 
required  for  a  Class  Ia  lifeboat. 

When  a  lifeboat  of  this  class  is  constructed  of  metal,  an 
addition  is  made  to  the  cubic  capacity  of  the  airtight  com- 
partments so  as  to  make  the  buoyancy  equal  to  that  of  a 
wooden  boat. 

It  has  been  the  writer's  experience  when  allotting  the  number 
of  persons  to  lifeboats,  that  in  the  case  of  Class  Ib  boats,  the 
seating  accommodation  is  the  factor  which  determines  the  actual 
number  that  can  be  safely  placed  in  a  boat,  and  there  is,  therefore, 
very  little  advantage  to  be  gained  by  fitting  the  outside  buoyancy 


24 


SHIPS'    BOATS 


in  order  to  obtain  the  smaller  capacity  divisor,  viz.  9  as  com- 
pared with  10  for  the  Class  Ta  lifeboat. 

An  outline  section  of  a  Class  1b  lifeboat  is  shown  in  Fig.  2. 

Class  Ic. — Pontoon  lifeboats  having  a  well  deck  and  fixed 
watertight  bulwarks. 

Boats  of  this  type  are  very  rarely  constructed  for  passenger 
steamers  ;  the  Class  IIa  open  lifeboat  appears  to  be  the  most 
popular,  owing  to  its  adaptability  for  close  stowage. 

The  characteristic  features  of  this  class  of  boat  are  that 
the  occupants  are  accommodated  above  the  deck,  and  it  is 
dependent    for    its   reserve   buoyancy    on    the    efficiency    of 


I 


m 


riXCO  THWARTS  AND    BULWARKS. 


kWC 


Fio.  3. — Midship   section  of   Class  lo  pontoon  lifeboat  with  well-deck  and 

fixed  bulwarks. 


the  watertight  sub-division  of  the  hull,  and  not  upon  watertight 
air-cases. 

Non-return  valves  are  fitted  in  the  well  for  efficiently  clearing 
the  deck  of  water. 

When  the  boat  is  fully  loaded  the  freeboard  must  be  such 
that  provision  is  made  for  a  reserve  buoyancy  of  not  less  than 
35  per  cent. 

Fixed  watertight  bulwarks  are  fitted  above  the  deck,  for  the 
protection  of  the  passengers,  to  which  are  secured  the  thwarts 
and  side  seats. 

The  design  of  this  class  of  boat  is  generally  admitted  to  be  a 
good  one,  having  ample  stability  and  giving  a  fair  amount  of 
protection  to  the  occupants.  The  efficiency  of  the  watertight 
compartments  depends  upon  good  workmanship,  and  also  the 
careful  oversight  of  the  inspector. 


CLASSIFICATION   OF   BOATS 


25 


The  details  of  construction  are  dealt  with  in  Section  E  of 
Part  IV.,  and  a  midship  section  is  shown  in  Fig.  3. 


Class  IIa. — Open  lifeboats  having  the  upper  part  of  the  side 
collapsible. 

A  boat  of  this  type  is  constructed  of  two  thicknesses  of  wood, 
the  combination  being  sometimes  larch  and  yellow  pine,  but  the 
better  class  and  more  reliable  boats  have  their  hulls  made  up  of 
two  thicknesses  of  mahogany.  There  is  considerable  difference 
in  design  from  the  pontoon  type  of  lifeboat. 

Reference  should  be  made  to  Fig.  4  which  shows  in  outline 
the  midship   section   of   a   Class    IIa   lifeboat.      The   reserve 


BULWARK  AND  THWARTS  RAISED 


BULWARK  AND  THWAfTTS  COLLAPSED 


Fio.  4. — ^Midship  section  of  Class  IIa  open  lifeboat  with  collapsible  bulwarks. 

buoyancy  is  provided  by  watertight  metal  air- cases  fitted  at 
the  sides  of  the  boat,  and  external  buoyancy  made  up  of  solid 
cork  attached  in  a  similar  manner  as  approved  for  the  Class  Ib 
lifeboats. 

The  wood  covering  to  the  buoyancy  air  tanks  forms  a  partial 
deck  to  the  boat,  which  provides  seating  accommodation  for  the 
occupants.  Additional  accommodation  is  given  by  thwarts  and 
side  seats  which  hinge  above  the  deck  and  become  automatically 
secured  in  position  by  the  bulwarks. 

The  bulwarks  are  made  to  hinge  down  on  the  declc  to  facilitate 
stowage. 

The  internal  metal  air-cases  must  have  at  least  1*5  cubic  feet, 
and  the  external  buoyancy  of  solid  cork  at  least  0*2  cubic  feet, 
for  each  person  the  boat  is  able  to  accommodate. 

There  is  also  what  is  termed  a  modified  Class  IIa  Open  Life- 
boat.   To  obviate  the  necessity  of  fitting  the  external  buoyancy,  an 


26 


SHIPS'   BOATS 


addition  has  been  made  to  the  internal  metal  air  cases.     Most  of 
the  Class  IIa  lifeboats  are  now  constructed  on  these  lines. 

The  details  of  construction  and  method  of  obtaining  the 
correct  number  of  persons  which  can  be  allotted  to  this  class  of 
boat,  are  dealt  with  in  Section  D  of  Part  IV. 

Class  IIb. — Pontoon  lifeboats  having  a  weU-deck  and  collapsible 
bulwarks. 

The  hull  of  this  class  of  boat  is  constructed  in  the  same  way 
as  a  Class  Ic  lifeboat,  the  only  difference  being  in  the  type  of 
bulwark.  To  facilitate  stowage  the  bulwarks  of  the  Class  IIb 
lifeboat  hinge  down  on  the  deck. 

BULWARK  AND  THWARTS  RAISED 
STOWING  POSITION  OF  BULWARK  ETC 

a. 


U.WU 


Fio.  5. — ^Midship  section  of   Class  Ub  pontoon  lifeboat  with  well-deck  and 

collapsible  bulwarks. 

Constructive  details  are  dealt  with  in  Section  E  of  Part  IV., 
and  a  midship  section  is  illustrated  in  Fig.  5. 


Class  lie. — Pontoon  lifeboats  havitig  a  flush  deck  and  collapsible 
bulmarks. 

The  general  arrangement  of  construction  is  very  similar  to  a 
Class  IIb  lifeboat,  except  that  the  latter  possesses  a  well  in  the 
deck  and  the  Class  lie  has  a  flush  deck.  Efficient  arrangements 
must  be  fitted  for  speedily  clearing  the  deck  of  water.  Two  tons 
of  water  must  be  cleared  from  the  deck  of  a  boat  28  feet  in  length 
in  20  seconds,  as  compared  with  60  seconds  in  a  Class  Ic  or  IIb 
lifeboat.  Non-return  valves  or  scuttles  are  fitted  in  the  deck 
and  bulwarks,  the  number  of  which  depends  on  the  experience 
gained  from  the  flooding  tests. 


CLASSIFICATION    OP    BOATS 


27 


Details  of  construction  are  referred  to  in  Section  E  of  Part  IV. 

Considerable  care  and  oversight  need  to  be  exercised  on  the 
part  of  ships'  officers  and  inspectors  in  keeping  the  pontoon 
lifeboats  periodically  under  a  close  survey.  Usually  these  boats 
are  stowed  in  tiers,  and  very  rarely  come  into  the  operation  of 
boat  drill.  The  influence  of  the  weather  has  a  detrimental  effect 
on  the  watertightness  of  the  hull,  if  the  deck  is  of  wood.  Boats 
constructed  of  steel  can  more  easily  be  divided  and  each  compart- 
ment made  independently  watertight.  Probably  the  decks  of 
such  boats  are  not  subjected  to  the  same  damaging  effect  from 
the  weather  as  the  wooden  boat,  but  the  necessity  of  periodical 
survey  for  the  prevention  of  corrosion  is  just  as  great  in  the  steel 
boat. 


FLUSH     DECK 


7W=* 


ICHT       COMP 


I 


^rt|vient 


I  t 

I  I 


Fio.  C. — Midship  eection  of  Class  lie  pontoon  lifeboat  with  flush  deck  and 

oollapsible  bulwarks 

The  American  Balsa  Company,  the  successors  to  the  Welin 
Marine  Equipment  Company,  construct  a  large  number  of  steel 
boats  of  this  class,  which  are  known  as  the  "  Lundin  "  Decked 
Lifeboat ;  Messrs.  Mechan  and  Sons  of  Glasgow  have  also  con- 
structed boats  of  similar  type  for  the  Welin  Davit  Co. 

Information  dealing  with  freeboard  and  the  method  of 
obtaining  the  correct  number  of  persons  that  can  be  assigned  to 
a  boat,  is  given  in  Section  E  of  Part  IV. 

A  middiip  section  is  shown  in  Fig.  6. 


Class  III, — Open  boats  which  have  not  the  huoyaticy  required  for 
lifeboats  of  Class  /. 

The  construction  of  this  class  of  boat  is  identically  the  same 
as  a  Class  Ia  lifeboat,  with  the  one  exception  that  buoyancy 
air-cases  are  not  fitted.      If  it  forms  a  part  of  the  statutory 


28 


SHIPS'    BOATS 


equipment  of  a  vessel,  it  should  be  fully  equipped  in  every  detail 
as  a  Class  1a  lifeboat.  This  provision  is  often  lost  sight  of  by 
shipbuilders  and  boatbuilders. 


Fio.  7. — Midship  seotion  of  Class  III.  open  boat. 

Further  reference  is  made  to  this  type  of  boat  in  Section 
C  of  Part  IV. 

A  midship  section  is  shown  in  Fig.  7. 


SECTION  C— FORM,  STABILITY,  STRENGTH,  AND 
CAPACITY,  OF  SHIPS'  BOATS. 

FORM. 

It  has  been  the  aim  of  the  author  throughout  the  preparation 
of  this  text-book,  to  deal  essentially  with  the  practical  appli- 
cation of  the  subject,  and  to  avoid  all  abstruse  theoretical 
considerations  which  would  hinder  the  reader  with  a  Umited 
knowledge  of  the  Science  of  Naval  Architecture,  from  obtaining 
an  intelligent  grasp  of  the  main  features  which  have  to  be  ob- 
served in  determining  a  suitable  form  and  general  design,  before 
commencing  construction  on  a  ship's  boat  which  ha§  to  form 
part  of  the  statutory  equipment  of  a  merchant  vessel  as  a  Ufe- 
saving  appliance. 

Practice  and  theory  are  inseparable,  and  both  must  be 
correlatively  associated  with  any  attempt  to  deal  in  detail  with 
the  present  subject.  It  would  be  just  as  futile  and  useless  to 
commence  the  building  of  a  house,  without  previously  taking 
the  precaution  of  considering  the  suitability  and  strength  of  the 
foundation,  as  to  discuss  the  practical  details  of  ship  or  boat- 


FORM,  STABILITY.   STRENGTH,    AND  CAPACITY    29 


l)iiil(lm>;  without  due  reference  being  given  to  the  main  theoietical 
I  mvestigationa  connected  with  the  deai^n. 

Progreaa  in  all  Engineering  Science  has  been  largely  due  to 
^tlie  personal  initiative  of  the  "investigator"  who  has  given  to 
I  the  practical  man  in  later  years  much  financial  advantage  as  one 
I  of  the  results  of  his  work  and  devotion, 

We  should,  therefore,  not  think  lightly  of  theory  in  ite  relation 
I  to  the  subject  of  ships'  boata,  even  if  it  can  only  be  regarded 
1b6  the  "offspring''  of  the  much  larger  and  more  important 
[Science of  Naval  Architecture. 

As  far  aa  this  book  is  concerned  theory  has  been  given  it* 
[  correct  hcus  »tandi  in  the  order  of  treatment. 

During  the  past  ten  years  there  has  l)een  ample  opportunity 

P  provided  for  students  t*)  become  thoroughly  acquainted  with  all 

^the    theoretical    considerations    associated    with     shipbuilding, 

I  through  the  medium  of  many  excellent  text-books  written  on  the 

isubject.     The  author  has,  therefore,  kept  this  section  of  the 

f  treatise  within  defined  limitations,  with  the  exception  of  that 

portion  which  deals  with  initial  stability  and  the  influence  of 

free  water  in  a  boat  on  its  stability,  and  as  tlieuc  featuri}s  have 

such  a  regulating  influence  on  Form,  the  matter  has  been  discussed 

^H  at  some  lei^h. 

^K        Form  and  Stability  cannot  actually  be  separated  into  two 
^^V  distinct  section.^  lor  discussion  :  one  b  the  outcome  of  the  other. 
^H         Before  determining  the  most  suitable  dimensions  for  a  life- 
boat in  order  that  it  may  safely  carry,  ia  a  seaway,  the  allotted 
number  of  persons,  it  is  of  importance  that  we  should  under- 
fltand  some  of  the  salient  features  which  influence  the  fonu  of  a 

■  boat. 
There  has  been  too  great  a  tendency  in  past  years  for  certain 
boatbuilders  to  fine  down  the  sections  of  their  boats,  in  order 
to  save  material,  and  provide  less  work  in  the  operation  of 
planking.  Keen  competition  in  busy  shipbuilding  centres, 
without  the  exiatence  of  a  recognised  scheme  of  scantlings  or 

I  minimum  specification,  has  been  responsible  for  nlany  doubtful 
Efeboats  being  placed  on  board  merchant  vessels. 
Very  little  consideration  was  given  to  the  undei-watcr  form, 
«id  the  common  practice  was  to  build  the  boat  "  to  the  eye  " 
without  the  use  of  even  a  midship  section  mould.  A  great  deal 
depends  on  the  way  the  garboards  or  sandstrakes  and  their 
Adjacent  strakes  are  worked,  as  to  what  measure  of  fullness 
the  boat  will  take.  If  the  rise  of  floor  comes  up  too  quickly 
to  suit  the  breadth,  or  the  bilge  planking  is  worked  in  surJi 


J 


30 


SHTPS'    BOATS 


iiiaiinei-  08  to  narrow  the  Iteaiii  of  the  boat,  a  too  frequent  use  of  1 
ahores  has  consequently  to  be  made  to  preserve  the  fonn  of  the  1 
boat,   to  suit   the  specified  dimensionH.     In  the  effort  to  save 
matflrial  and  labour,  suitability  of  form  is  often  sacrificed  for 
the  convenience  of  working,  and  these  objectionable  practices 
make  one  often  doubt  the  seaworthy  qualities  of  the  boat. 

It  is  generally  accepted  among  practical  men,  tliat  in  order 
to  preserve  efficient  solein^  of  the  plank  !andinj;s,  upon  wliich 
the  watertiji;)itne8a  of  a  boat  so  much  depends,  and  to  maintain 
a  parallel  breadth  for  the  landings,  it  is  most  essential  that 
section  moulds  should  be  used  at  amidships  and  the  quarter 
lengths. 

The  Life-saving  Appliances  Rulea  of  1913  insisted  that  in 
open  lifeboats  of  Class  I.  (they  were  then  known  as  Section  A 
lifeboats)  the  boat's  half-girth  amidships,  measured  outside  the 
planking  from  the  centre  line  of  the  keel  to  the  top  of  the  gunwale, 
should  be  at  least  equal  to  eighty-eight  hundredths  of  the  sum 
of  the  boat's  depth  inside  and  half  its  maximum  breadth  amid- 
ships, iM.    ^         =  88%,  and  that  the  mean  of  the  half-girths 

measured  in  the  same  manner,  at  two  points,  one  quarter  of  the 
length  of  the  boat  from  the  stem  and  stempost  respectively, 
should  be  at  least  equal  to  eight-tenths  of  the  sum  of  the 
depth  inside  and  half  the  maximimi  breadth   amidships,  i.e. 

p*^  !,  =  «»%■ 

If  a  lifeboat  did  not  comply  with  this  girth  rale,  the  number 
of  persons  to  be  carried  was  reduced,  by  dividing  the  capacity 
of  the  boat  by  the  larger  divisor  12  instead  of  10,  unless  it  was 
proved  by  actual  test  afloat,  with  the  fuU  equipment  on  board, 
that  the  boat  had  sufficient  seating  accommodation  for  the  full 
number  of  persons,  without  interfering  with  the  oarsmen. 

With  tlie  1914  issue  of  the  Life-saving  Appliances  Eides,  the 
girth  rule  was  deleted,  partly  as  a  result  of  the  recommendations 
of  the  Departmental  Committee  on  Boats  and  Davits. 

The  girth  rule,  nevertheless,  possessed  an  advantage  wliich 
prevented  the  builder  from  fining  away  the  ends  of  the  boat 
after  he  had  secured  the  correct  depth  and  breadth  at  the  midship 
section. 

For  some  time  there  has  been  a  unanimous  expression  of 
feeling  among  boatbuilders  that  there  should  be  some  definite 
rule  or  dimensions  given,  which  would  ensiire  a  minimum  fullness 
of  form  being  maintained  in  open  boats  of  Classes  1.  and  III. 


I 

I 

I 

1 

I 

1 

1 

1 

I 


FORM,  STABiUTV,  STKENOTH.  AND  CAPACITY    31 

While  it  is  considered  undesirable  tfl  place  uimetessaiy 
'reetrictionB  on  design,  it  is  essential  that  a  reasonable  amount 
of  fullness  should  be  preserved  towards  the  ends  of  a  boat,  and  that 
a  sufficient  volume  of  capacity  be  provided  to  adequately  support 
the  full  number  of  peraons  carried. 

Apart  from  the  considerations  of  stabrlity,  it  has  been  found 
necessaiy,  with  a  standard  depth  for  the  thwarts  to  be  fitted 
below  the  gunwale  in  boats  of  Classe«  I.  and  III.,  to  preKerve  a 
medium  rise  of  floor,  alsn  that  the  fulhictss  of  underwater  form 
be  carried  well  forward  and  aft.  in  order  to  "  wing  out "  and 
satisfactorily  house  the  buoyancy  air-caaes,  without  encroaching 
unnecessarily  on  the  space  between  the  tank  cleading  for  the 
reception  of  the  lower  aeats. 

Considerable  discussion  has  arisen  from  time  to  time  as  to 
the  best  form  which  should  be  preserved  in  a  boat  constructed 
for  the  purpose  of  containing  a  large  number  of  occupants,  and 
where  arrangemeats  are  made  for  the  pmpulsion  by  the  aid  of 
oars  or  with  the  assistance  of  sails. 

Formation  dI  Bow.^Atthou^h  it  is  the  usual  practice  to 
avoid  the  fitting  of  a  bow  buoyancy -tank  owing  to  the  difficult 
shape  for  construction,  yet  it  is  considered  by  the  writer  that  two 
long  metal  air-cases  placed  in  the  bow,  one  on  each  side  of  the 
lifting  hook,  have  an  important  value  in  providing  the  boat  with 
an  easy  lift  on  enterinj;  a  wave,  should  a  large  volume  of  water 
be  taken  on  board. 

The  majority  of  boate  are  cunstnicted  with  their  quarter- 
Ivngth  sections  at  the  forward  and  after  ends  practically  alike. 

The  bow  shoidd  be  comparatively  fine  in  form  to  reduce  the 
shock  of  each  wave  or  of  a  running  sea,  and  the  possession  of  a  full 
st«rn  steadies  the  boat  and  prevents  the  bow  from  hammering 
unduly  over  short  waves  or  rising  on  end  against  a  high  breaker. 

There  must  be  a  reasonable  amount  of  surplus  buoyancy 
forward,  so  as  to  enable  the  boat  to  rise  to  each  wave,  but  not 
enough  to  lift  it  high  above  the  wave.  In  this  respect  it  would 
be  an  advantage  in  all  open  lifeboat^^  of  Class  I.  to  have  the  bow 
tieckeii  over  for  a  short  distance,  as  is  done  in  the  majority  of 
motor  lifeboats,  which  allows  the  boat  to  run  into  a  wave  and 
rise  through  it  without  taking  much  water  on  board. 

Formation  ot  Stern. — The  stern  should  be  made  with  full 
quarters,  i.e.  continuing  the  breadth  weU  aft,  with  comparatively 
line  hnes  below  the  full  quartera,  so  that  when  the  bow  is  rising 
to  a  wavC)  the  broad  stem  with  less  surplus  buoyancy  has  a  grip 
of  the  water  and  helps  the  boat  to  maintain  headway  and  stability. 


32  SHIPS"    BOATS 

Sheer  lias  considerable  influeace  in  lielpin^  to  preserve 
various  qualities  referred  to.  Wliea  sailing  to  w-indward,  a  good 
broad  stem  with  a  moderately  line  and  high  bow  and  a  deep 
heav}'  keel,  provide  the  boat  with  many  valuable  characteristics, 
wliich  help  to  maintain  a  condition  of  safety  when  in  a  seaway 
with  a  full  load. 

Influence  ol  Dimensions  on  Form.^Uitherto,  there  has  becD 
a  tendency  among  the  staff  of  the  shipbuilder  to  use  dimensiona 
for  ships'  boats  which  are  obviously  unsuitable  to  secure  the  best 
results  for  stability.  A  certain  number  of  a  crew  is  carried  on  a 
cargo  vessel,  and  provision  has  to  be  made  for  supplying  boats 
on  each  side  of  the  vessel,  of  sufficient  capacity'  to  accommodate 
the  total  number  of  persona  on  board.  Dimensions  are  then 
selected,  which,  when  multiplied  together  with  the  coefficient  6, 
give  a  certain  capacity  which  ia  considered  sufficient  to  provide 
the  necessary  accommodation,  and  will  meet  the  requirements 
of  the  Life-saving  Appliances  Rules.  The  latitude  thus  given, 
owing  to  the  absence  of  any  guiding  factors,  has  been  responsible, 
in  many  instances,  for  dimensions  going  to  the  boatbuilder 
whicii  the  latter  knows,  frtmi  his  own  practical  experience,  to  be 
moat  unsuitable.  It  very  often  happens  when  the  effort  is  made 
to  provide  accommodation  for  the  whole  of  the  crew  in  one  boat 
on  each  aide,  that  the  boat  ia  too  large  for  the  crew  to  con- 
veniently handle. 

In  the  1914  issue  of  the  Life-saving  Apphancea  Rules,  it  states 
that  in  working  up  the  capacity  of  an  open  lifeboat,  the  depth 
is  always  to  be  limited  to  45%  of  the  breadth.  This  percentage 
has  always  been  a  "  bone  of  contention  "  with  boatbuilders  and 
shipbuilders ;  the  former  consider,  and  rightly  so,  that  a  depth 
equal  to  45%  of  the  breadth  does  not  give  such  a  stable  boat  as 
one  with  a  depth  of  iO%  or  at  the  most  42%  of  the  breadth. 

The  thwarts  are  fitted  at  a  standard  depth  below  the  gun- 
wale, and  the  weight  of  persons  is  kept  down  in  the  boat  as  low 
as  will  be  consistent  with  the  provision  of  a  auflicient  freeboard. 

Take  a  well-known  standard  size  of  oj>en  lifeboat  of  Class  Ia, 
viz.  24'  0"x  7'  O^x  3'  0°.  By  fitting  lower  seats,  this  type  of 
boat  will  accotomodate  32  persons,  and  no  more,  without  unduly 
interfering  with  the  free  use  of  the  oars.  This  particular  depth 
is  40%  of  the  breadth.  Suppose  the  depth  is  increased  to  45% 
of  the  breadth,  it  stands  to  reason  that  by  increasing  the  depth 
another  4  inches  you  will  not  secure  another  square  foot  of  area 
for  the  accommodation  of  an  additional  person.  Although  you 
have  increased  the  freeboard  4  inches,  the  weight  or  the  centre 


I 
I 


I 
I 

I 


FORM.  STABILITY,  STRENGTH,  AND  CAPACITY    33 

of  gravity  of  32  puriKiiiB  has  beeji  raised  a  siniilar  aniimiit,  which 
has  reduced  the  metaceutric  height. 

As  will  be  seen  later  on  in  this  section,  a  certain  amount  of 
latitude  can  be  j^iven  to  the  underwater  form  of  a  bi»at,  without 
seriously  interfering  with  its  seaworthy  i:]uahtics. 

The  aim  is  to  find  the  happy  medium  between  the  flat  or 
full-formed  underwater  section  aud  the  section  possessing  gteat 
rise  of  floor,  which  will  give  a  satisfact^try  type  of  boat  and  suitable 
for  the  majority  of  the  circumstances  in  which  it  may  be  required 
t"  operate. 

CoefBcleat  ol  Form. — As  a  result  of  the  accumulation  of 
information  from  various  sources,  it  seems  very  desirable  th(it  a 
miuimum  coefficient  of  form  should  be  insisted  upon,  so  that 
some  of  the  difficulties  already  referred  to  might  be  avoided. 
This  coefficient  is  suggested  as  being  not  less  than  Qi. 

The  internal  capacity  of  the  boat  is  measured  as  explained 
on  pp.  81-83,  and  the  result  divided  by  L  X  B  X  D  ;  L  being 
the  lengtii  to  inside  of  plauk  rabbets  measured  at  the  stem  and 
atempost,  B  the  greatest  breadth  at  middle  of  lenjith,  measured 
to  inside  of  planking,  aud  D  the  depth  amidships  from  to])  of 
gunwale  to  inside  of  planking  at  keel. 

With  this  limiting  coeflicient  of  form,  tlie  required  amount  of 
underwater  fullness  is  assured,  but  to  ask  the  boatbuilders  to 
construct  open  lifeboats  of  Class  I,  and  boats  of  Class  III.  to  this 
required  coefficient,  without  some  guiding  offsets,  would  make  the 
operation  somewhat  difficult,  unless  the  dimensions  of  boats  and 
moulds  were  standardised. 

These  oSsets  are  now  in  operation,  whereby  the  boatbuilder 
can  conveniently  and  rapidly  apply  a  check  to  the  form  of  the 
boat  aa  the  planking  is  in  progress. 

Reference  is  made  tn  Fig.  18  un  page  6,5. 

A  water  plane  level  is  taken  at  half  the  depth  amidships, 
and  the  breadth  on  this  water-line  amidships  must  be  '96  of 
the  full  breadth  of  the  boat,  and  the  breadth  measured  on  the 
same  water-line,  at  the  quarter- lengths,  must  not  be  leas  than 
■77  of  the  full  breadth  of  the  boat. 

Take,  for  example,  a  lifeboat  of  Class  Ia  with  the  following 
dimensions  :  24'0'  X  75'  X  30'. 

The  breadths  measured  on  a  water-line  at  the  half-depth 
amidships  would  be —     - 


Amidships  :  7D'  X  -90  =  72'  (7'  2i'). 

At  quarter-lengths  :  7-5'  X  ■77  =  5-78'  (u'  9)' 


34  SHIPS'    BOATS 

Having  these  pointe  fixed  in  the  three  sectioDS  of  the  boat,  i 
is  necessary  to  consider  the  most  suitable  rise  of  floor,  and  the 
writer  has  come  to  the  conclusion  after  experience  with  many 
types  of  boats,  that  the  best  underwater  form  for  an  open  lifeboat 
of  Class  Ia  is  obtained  by  allowing  a  rise  of  floor  of  5J  to  6  in. 
in  a  half-breadth  of  4  ft.  6  in.,  that  is,  the  beam  of  the  boat 
would  be  9  feet.  Setting  up  this  rise  of  floor,  as  shown  in  Fig.  18, 
for  a  30-tt.  lifeboat,  the  sections  for  boata  of  intermediate  length  . 
between  30  and  IC  feet,  are  brought  down  to  this  line  AB. 

Wallsided  topaides  are  an  advantage  to  the  boat  in  maintaining 
stability,  and  this  is  assured  by  the  provision  of  the  '96  offset,  at   , 
the  midship  section. 

The  Board  of  Trade  recommend  in  their  latest  instructions  j 
that  all  open  boats  of  Class  I.  be  constructed  with  a  rise  ot  £ 
of  6  in.  in  4  ft. 

Form  of  Bilge. ^.Aji  easy  bilgo  is  absolutely  necessary  so  as   ■ 
to  allow  for  a  gradual  soleing  to  be  taken  off  the  plank  landiQgs. 
A  sharp  bilge,  or  one  which  takes  the  shape  of   a  ban'el, 
provides  a  bad  form  for  sailing. 

A  sudden  breaking  off  from  the  wallsided  topside  to  a  straight 
rise  of  floor  from  the  keel,  ia  detrimental  to  the  sailing  qualities 
and  stability  of  a  boat,  when  it  is  heeled  over  suddetJy  by  a  gust 
of  wind. 

If  the  midship  form  gives  the  appearance  ot  resembling  the 
circumference  of  a  circle,  then  the  boat  will  be  more  easily 
inclined  when  under  way  with  sails  set,  than  if  she  were  designed 
with  wall  sides  down  to  the  half-depth,  and  po.saeasing  an  easy 
bilge  running  into  the  floor  having  the  amoimt  of  rise  as  shown 
in  Fig.  18. 

To  enable  the  boatbuilder  to  readily  apply  a  check  on  the 
form  of  his  boat  as  construction  proceeds,  a  table  (No,  VI.)  has 
been  drawn  up  showing  the  breadths  at  half  the  midship-depth 
at  the  midship  section  and  the  quarter-length  sections,  measured 
to  the  inside  of  the  planking  or  the  uutaide  of  the  timbers. 
These  figures  give  important  spofa  in  the  outline  of  the  sections, 
and  with  the  rise  of  floor  suggested,  little  difficulty  should  be 
experienced  in  making  suitable  moulds. 

A  sudden  break  from  the  perpendicular  topsides  to  the  floor, 
makes  a  line  of  weakness  in  an  open  boat  in  way  of  the  soleing  of 
the  bilge  plank  landings,  and  it  therefore  becomes  necessary  to 
increase  the  thickness  of  the  bilge  planking. 

In  the  case  of  an  open  boat  of  Class  I.,  or,  as  a  matter  of  fact, 
in  any  type  of  boat,  one  of  the  weakest  spots  in  the  stmcture  is 


FORM,  STABILITY,  STRENGTH,   AND   CAPACITY    35 

at  the  bilge,  and  the  strength,  to  some  extent,  is  made  up  by  the 
fitting  of  a  stringer  of  the  same  scantlings  as  the  rising,  and 
secured  to  alternate  timbers  by  through  fastenings  clenched 
over  rooves. 

TABLE   VI. 

MiNiHUH  Breadths  to  Inside  op  Planking   at  Half  MrosHip-DErTH  for 

Open  Boats  of  Classes  I.  and  III. 


Dimensions  of  boat. 

Breadth  at  midship.           ' 

Breadth  at  quarter- 
0-83'               6' 

length. 

30-0' X  90' X  3-76' 

8r.4' 

8'     6}* 

10" 

29-0'  X  8-76'  X  3-6' 

8-30' 

8'    3S'' 

6-64' 

0' 

li' 

28-0' X  8-6' X  3-5' 

806' 

8'    Of"     1 

6-45' 

6' 

3^ 

27-0' X  8-26' X  3-4' 

7-82' 

r  9r 

6-25' 

6' 

26-0' X  8-0' X  3-25' 

7-68' 

r  r 

606' 

6' 

or 

26-0' X  7-76' X  315' 

7-34' 

r  4r 

5-87' 

6' 

lor 

24-0' X  7-6' X  3-0' 

710' 

7'     ir 

5-68'     . 

5' 

sr 

23-0' X  7-5' X  2-9' 

710' 

r  li" 

6-68' 

5' 

sr 

22-0' X  7-25' X  2-75' 

6-86' 

6'  lor 

5-48' 

5' 

5r 

21-0'x7'0'x2-7' 

6-62' 

iV    ll"      ! 

5-29' 

5' 

3r 

200' X  0-75' X2f»' 

(i-38' 

(}'  4r   , 

510' 

5' 

ir 

19-0' x6T»'x  2-5' 

614'. 

iv  1  r 

4-9()' 

4' 

lor 

180' X  6-25' X  2-4' 

5-00' 

5'  lor 

4-71' 

4' 

8.r 

17-0' X  6-0' X  2-35' 

5-66' 

'y  IV    , 

4-52' 

4' 

or 

16-0' X  5-75' X  2-3' 

5-42' 

y      5 

1 

4  33' 

V 

r 

Note. — The  Board  of  Trade  have  adopted  the  factor  -77  for  the  quarter- 
length  breadth  as  a  minimum*  owing  to  the  consideration  that  in  very  small 
boat8  it  is  difficult  to  work  the  planking  to  a  fuller  form.  They,  however, 
strongly  recommend  that  the  breadth  of  waterplan'3  should  be  made  as  great 
as  possible  consistently  with  easy  w^orking  of  the  planking. 

Owing  to  the  great  width  in  comparison  with  the  depth, 
there  is  not  the  amount  of  latitude  in  boats  of  Class  Ic,  IIa,  IIb 
and  lie  as  boats  of  Classes  I  a,  Ib  and  111.  for  variation  of  form. 
There  does  not  appear  to  be  much  doubt  about  the  dimensions 
of  the  former  as  these  have  been  practically  standardised  as  a 
result  of  repeated  stabiUty  tests. 

Breadth  in  relation  to  Length. — In  dealing  with  the  dimensions 
of  boats  of  Classes  Ia,  Ib,  and  III.  (when  the  latter  form  a 
part  of  the  statutory  equipment  of  a  vessel),  useful  formulae  can 
now  be  used  which  will  act  as  a  guide  for  the  boatbuilder  and 
the  shipbuilder  in  securing  a  suitable  breadth  for  a  particular 
length  of  boat.  If  these  are  used,  it  will  ensure  a  breadth 
being  worked  which,  from  the  results  of  stability  tests,  is  con- 
sidered to  be  the  minimum  for  boats  of  these  classes. 


36  SfflPS'   BOATS 

The  following  formulae  will  serve  the  purpose  of  quickly 
obtaining  the  minimum  breadth  required,  these  being  in 
accordance  with  the  regulations  issued  by  the  Board  of 
Trade. 

The  breadth  of  the  boat  may  exceed  the  breadth  obtained 
by  these  formulae  by  not  more  than  3  in.,  but  the  depth  in 
that  case  must  not  exceed  that  obtained  by  the  recognised 
formula  referred  to  in  the  next  clause. 

For  boats  24  ft.  in  length  or  over — 

T*      1.1   •     r    X      Length  in  feet  +  6 

Breadth  m  feet  =  — ^^       . 

4 

For  boats  22  ft.  in  length  or  under — 

T»      j^i   •    J    ^      Length  in  feet  +  7 

Breadth  m  feet  = r 

4 

For  boats  between  22  ft.  and  24  ft.  in  length — 

Breadth  =  7  ft.  6  in. 

Depth  in  relation  to  Breadth. — ^In  order  to  keep  the  weight 
of  the  persons  as  low  down  in  the  boat  as  will  be  consistent  with 
the  satisfactory  provision  made  for  the  use  of  the  oars  from  the 
thwarts,  and  at  the  same  time  provide  a  freeboard  which  will 
ensure  a  suflScient  range  of  stability,  the  following  formula  has 
been  adopted  by  the  Board  of  Trade  : — 

T^    .1.  •    X    X      '42  (length  in  feet  +  6) 
Depth  m  feet  = ^ — ^ — j — ^ 

Before  leaving  the  subject  of  Form,  reference  is  made  here 
to  the  Welin  Patent  Overframe  Type  of  davit,  which  allows  the 
boat  to  stow  in  the  inboard  position,  on  chocks  secured  to  the 
davit.  It  is  essential,  when  lifeboats  are  to  be  stowed  in  these 
davits,  that  dimensions  should  be  taken  from  the  drawings 
supplied  by  the  firm,  giving  the  correct  curvature  of  the  arms, 
to  enable  the  boats  to  lie  "  neat  and  snug  "  to  the  shape  of  the 
davit  arm. 

Advantages  of  Standardisation. — The  writer  shares  the  opinion 
of  many  shipbuilders  and  boatbuilders,  that  a  great  improvement 
would  be  effected  if  boats  of  standard  dimensions  were 
recognised  and  worked  to,  provided  certain  salient  features  asso- 
ciated with  a  suitable  form  were  duly  observed. 

Such  a  scheme  would  considerably  increase  the  output,  and  the 
boatbuilders  would  be  limited  to  a  smaller  number  of  midship 
and  quarter-length  moulds.    The  firms  would  then  be  able  to 


^^    FORM.  STABILITY,  .STRENGTH.  .VND   CAPACITY    37 

standardise  all  tLfl  moulds  for  cnmhinatioiis,  such  as  deadwooda, 

Iapruns.  etc.  Material  could  be  ordered  iu  aaticipatiou  of  re- 
quirements and  with  less  risk  of  mistakes.  8t4^ck  boats  would 
Ibe  laid  down  in  jrreater  numbers  and  be  ready  for  emergencies. 
Uakers  of  patent  davits  could  standardise  their  fittings  with 
ipeater  certainty  of  being  able  to  provide  for  the  full  load,  and 
the  work  of  the  shipbuilder  would  be  lessened  through  having 
detinite  data  on  which  to  base  the  calculations  for  the  size  of 
davits. 
The  Admiralty  have,  for  many  years,  worked  to  a  fixed 
Btandanl  for  dimensions,  to  suit  each  particular  type  of  boat, 
A  complete  set  of  lines  is  given  to  the  boatbuilder,  which  makes 
it  necessary  for  him  to  lay  off  the  offscta  on  a  scrieve  board,  in 
preparation  for  the  moulds.     The  specification  is  complete  in 

»  every  detail  and  calls  for  the  highest  class  of  workmanship.  A 
comparison  between  Admiralty  and  Mercantile  boats  will 
serve  no  useful  purpose :  the  former  are  designed  to  give  easy 
lines  for  rowing  and  sailing,  they  are  not  fitted  with  buoyancy 
tanks,  and  the  crews  are  skilled  in  all  the  details  associated  with 
the  handling  of  a.  boat, 

Merchant  ships'  boata  are  heavy  in  scantling,  full  in  form, 
|,.ftnd   are  designed   to   meet   the   heavy  stresses   imposed  when 
bwered  from  the  davits  with  the  full  load,  and  also  in  the  case 
f,ti  a  Ufeboat  lowered  in  an  emergency  from  a  passenger  vessel, 
where  the  majority  of  the  occupants  would  be  undisciphned, 
■  probably  in  a  condition  of  panic,  and  ignorant  of  the  manage- 
ment of  a  boat  in  a  seaway. 

Snitable  Dimensiom. — A  list  of  suitable  sizes  for  open  boats 

[  Claeaee  Ia.  Ib,  and  111.,  has  been  drawn  up  and  shown  iu 

Table  VH.    These  size^  will  cover  all  the  requirements  of  the 

iupbuilder  between  boat«  of  16  and  30  feet  in  length.    They  have 

sen  framed  with  the  purpose  of  allowing  tlie  boatbuilder  to 

e  the  smallest  number  of  section  mouhls. 

Ill  column  1  the   dimensions  are  shown  in  feet  (decimals), 

1  boatbuildcrs  are  recommended  to  accuat4)tu  themselves  to 

e  of  these  figures,  as  they  simplify  calcidations. 
In  column  2  the  same  dimensions  are  shown  in  feet  and  inches. 
(\)hitmi  3  gives  the  capa<?ity  of  each  boat,  based  on  the 
L  X  B  X  I)  X  0*0  formula.    If  meaaiu-ed  by  the  cuirect  method  of 
Stirling's  Rule,   the   capacity  should    be  greater,   but    iu    the 

I  majority  of  caseu  the  boats  will  not  take  more  pers<]D3  than  that 
given  by  the  use  of  the  first-named  rule  and  the  correct  unity 
pf  capacity. 


38  SHIPS'   BOATS 

The  numbers  ffiven  in  columnB  4  and  5  are  entirely  dependent 
on  the  provision  of  proper  seating  accommodation,  without  unduly 
interfering  with  the  free  use  of  the  oars. 


.       .         C»p«cltTln  1*0.  of  m 

stun.)         cnWctMt.      —  -       -  - 


(I) 


3-75' 


•2«-U'x8-75'x3-<l' 

3»0'X»75'x3n' 
•2H-0'x80'x3-5' 

37-«'x8-5'>:3-4' 
•27i''x8-25'x3-4' 

2llO'xH'2r>'x3-25' 
•2iCO'xB0'x3-25' 

2r.0'xH-0'x315' 
•2511' X  775' X  315' 

21-0'x7-7ft'x3-O' 
•21tl'x7-6'x3-0' 
•2:h)'x7-5'x2'«' 

22-0' X  7-5' X  2-75' 
•230'x7'25'x2-7C' 

210'x7-20'x2-7' 
•2rO'x7-0'x2-7' 


X3'4J' 


(2) 
3f>' V X9' if  X3' Vf 

au'Cxro-xS'?!' 
ao'o*x8'i»'x3'7r 

2B'0'x'''n'^'''" 

?8'0-x 

ZTtTx 

27'  0*  X  8'  3'  > 

2«'0'x8'3*x3'3' 

aircxB'irxs'S' 

25'0'x8'0-x3'lS' 
31.'0*x7'll*x3'13* 
24'0*x7'0'x3'(r 
24'0'xTfi'x3'0' 

23'0'xTli*x2'10i' 

22'0-x7'0'x2'B' 

22'U'x7'3'x2'ir 

2rO'x7'3'x2'83' 

2l'0-xT0'x2'8r 

20'0'xT0'x2'7r 

20'0*x6'l)'x2'7i' 

Ht'0*xtr(!-x2'(i' 

IH'O-x0'»'x2'4J'' 

17'0'xfi'0'x2'4i'' 

lll'U*xo'ir'x2'3ii* 


127 


12 


SugiffBtcd  iitandtrd  Sitcs. 

boaU  of  Clfua  III.  ^  10. 

IS  Ib  ia  Column  6  dfiMmda  ui 


Unit  of  capacity  for  liffboatn  of  Clans  1a  and 

Unit  of  oapMily  tor  lifuboaUt  ot  i'U^n    u      li. 

Number  ol  iM-raons  given  for  lifcbiisls  of  Ola 

the  provision  of  proper  seating  iiocontmDdation. 

There  is,  however,  uo  reason  why  this  list  could  not  be  limited 
to  the  8uggest<Hl  standard  sizes.  It  ia  a  short-sighted  policy  to 
cut  down  the  accoiuiiioilation  in  the  boats  to  the  barest  limits. 
The  writ«r  Is  hilly  aware  of  the  difficulti.-s  to  timl  Milhrli'iit  deck 
space  for  the  boats,  particularly  those  which  must  be  placed 
under  davits  in  a  large  passenger  liner  ami  the  previous  remarks 
apply  more  directly  to  the  ordinary  cargo  vessel. 


FORM,  STABILITY,   STRENGTH,  AND  CAPACITY     39 

A  limiting  capacity  of  125  cub.  ft.  is  placed  on  a  boat  which 
is  carried  on  a  vessel  and  has  to  comply  with  the  requirements 
of  the  Life-saving  Appliances  Rules. 

If  it  is  not  practicable  or  reasonable  in  any  case  for  a  ship  to 
carry  a  boat  of  the  minimum  capacity  prescribed  by  this  rule; 
the  Board  of  Trade  may,  in  their  discretion,  allow  a  boat  of 
smaller  capacity  to  be  carried  by  that  ship. 

In  small  "  puffers "  and  coasting  boats  running  a  short 
distance  beyond  the  smooth  water  Umits,  it  is  often  found 
impracticable  to  carry  a  boat  of  the  following  dimensions,  viz.  : — 
16'  0"  X  5*75'  X  23',  which  gives  the  limiting  capacity  of  125 
cub.  ft. 

In  Table  VIII.  is  shown  one  or  two  suggested  sizes  for  small 
lifeboats  of  Class  Ia  and  boats  of  Class  III.,  but  it  must  be  clearly 
understood  that  the  number  of  persons  which  may  be  safely 
allotted  to  these  boats  can  only  be  ascertained  after  actual 
trial,  for  it  is  the  writer's  experience  that,  with  the  amount  of 
equipment  which  is  required  to  be  placed  on  board,  serious 
interference  is  made  with  the  seating  accommodation. 

TABLE   VIII. 

PABTICITLABS    OF  OPKN   LiFEBOATS  (ClASS  1a)  AND   BoATS  OF  ClASS  III., 
BELOW    THE  LlMITINQ  CAPACITY   OF    125   CUBIC   FkBT. 


Dimensions  in  feet 
(decimals). 


(1) 
15-0' X  5-5' X  2-3' 
140' X  5-35' X  2-25' 
130' X  5-25' X  2-25' 

12-0' X5CX  2-2' 


Dimensions  in  feet  and 
inches. 


(2) 
li>'  0^X5'  0^   x2'  3r 
14'  O^'xS'  4rx2'  3"" 

13'  o^'xo'  r  x2'  r 

0"    x2'  2}" 


12'  O^'xS' 


Cai)aclly  in 
cubic  feet. 

LxBxDxOC 


(3) 

113 

101 

92 

79 


Appro3cimate 
No.  of  persons. 


(4) 
9 
8 
7 
5 


Note. — Application  must  be  made  to  the  Board  of  Trade  before  construction 
is  commenoed  on  any  boat  below  tho  capacity  of  125  cubic  feet,  for  permission 
to  use  the  proposed  dimensions.  This  action  is  taken  only  in  the  case  of 
a  boat  forming  a  part  of  the  statutory  equipment  of  the  vessel. 


Table  IX.  indicates  dimensions  of  Pontoon  lifeboats  of 
Classes  IIb  and  lie  and  open  boats  of  Class  IIa,  which  have 
been  supplied  to  passenger  vessels. 

Table  X.  gives  a  comparison  between  inches  and  decimals  of 
feet,  which  may  prove  useful  in  transposing  from  one  to  the 
other,  when  dealing  with  dimensions,  etc. 


40 


SfflPS'    BOATS 


TABLE   IX. 
Dimensions  of  Class  IIa  Open  Lifeboats. 


24' 
26' 
28' 
28' 
28' 
28' 
30' 


xT  if  xr  or  : 

x8'  or  xv  iir 

X  7'  e*  X  2'  2i^ 

X  8'  0*  X  2'  2r 

(T  X  8'  5^  X  2'  2|' 

0*  X  9'  0*  X  2'  ^' 

(T  X  ft'  0*  X  2'  2r 


0" 

or 
or 


43  persons. 

48 

60 

64 

67 

60 

(54 


Dimensions  of  Class  II b  Pontoon  Lifeboats. 

2f)'0'  X  8-0'  X  2'  0'  =  66  perepns. 
280'  X  8-6''  X  2'  r  =  63 
30-0'  X  9-0*  X  2'  2"  =  70 


»» 


»» 


Dimensions  of  (?lass  lie  Pontoon  Lifeboats. 

260'  X  8-0'  X  r    8r  =  52  persons. 
28-0'  X  90'  X  r    9*    =63 
300' X  9-0' X  r  lO'    =67 


♦t 


TABLE 

X. 

Inches. 

Feet  (decimals). 

Foet  (decimals). 

Inches. 

1 

•02 

•06 

i 

i 

•04 

•10 

lA 

i 

•06 

•16 

n 

1 

•08 

•20 

2| 

2 

•17 

•26 

3 

3 

•25 

•30 

34 

4 

•33 

•36 

*i\ 

6 

•42 

•40 

4} 

6 

•50 

•46 

5i 

7 

•68 

•50 

«i 

8 

•67 

•56 

Of 

9 

•75 

•60 

7A 

10 

•83 

•65 

n 

11 

•92 

•70 

8J 

12 

100 

•75 

•80 
•85 
•90 
•95 

1  -fUl 

1) 

»s 

103 

11? 

10 

STABILITY. 

In  the  proper  order  of  things,  stability  should  have  been 
dealt  with  before  the  subject  of  form,  because  it  is  due  to  in- 
formation obtained  as  the  result  of  stability  tests  that  we  are  in 


FOKM.  STABILITY.  STRENGTH.  AND  CAPACITY    U 


a  position  to  disciiBB  certain  salient  features  whicli  aSect  the 
'  shape  and  dimensions  of  ships'  boats.  It  suits  the  purpose  of 
b  this  text-book,  however,  to  proceed  on  the  present  lines. 

It  is  essential  to  refer  to  some  of  the  rudimentary  principles 
I  which  govern  the  general  question  of  stability. 

When  a  boat  is  inclined  from  her  position  of  reet  by  some 
t  external  force,  such  as  the  effect  of  wave  motion  or  wind  pressure 
Con  the  sail  area,  there  is  an  inherent  quality  possessed  by  the 
I  "boat,  which  at  once  comes  into  operation  in  opposition  to  this 
I>«xtema1  force,  tendir^  to  move  her  back  to  the  original  upright 
■  position. 

The  power  which  tends  to  upset  the  boat  is  the  dynamic 
f  force,  and  the  opposing  quality  to  inclination  possessed  by  the 
I  boat  is  a  static  force.  These  two  forces  are  always  in  operation 
i  during  the  period  a  boat  b  in  a  seaway,  and  when  the  dynamical 
B  forces  are  in  excess  of  the  statical  forces,  then  the  boat  capsizes. 
The  volume  or  amount  of  this  statical  fjuality,  or  as  expressed 
I.  in  technical  phraseology,  the  moment  of  the  force  which  is  being 
[  exerted  to  bring  the  boat  back  to  her  position  of  rest,  is  the 
I  measure  of  her  .stability. 

In  order  to  obtain  the  most  suitable  form  for  a  boat  to  ensure 
that  she  will  possess  sufficient  stability  to  enable  her  to  stand 
up  against  the  effect  of  heavy  seas  and  sudden  squalls  of  wind 
when  carrying  her  full  complement  of  persona,  it  is  necessary 
that  we  take  into  consideration  the  various  factors  which  have 
i  a  direct  bearing  upon  this  measure  of  stability. 

In  other  words,  we  have  to  find  out  "  what  to  put  into  the 
Kboat"  as  affecting  dimensions,  weights,  and  form,  which  will 
■give  the  greatest  measure  of  statical  stability  to  enable  her  to 
rcont«nd  against,  and  overcome  ail  reasonable  dynamical  forces, 
'  she  will  meet  with,  when  afloat. 

Displacement. — When  a  boat  is  floating  freely  and  at  rest 
in  still  wat€r,  she  displaces  a  certain  amount  of  fluid,  which,  if 
weighed,  must  equal  the  weight  of  the  boat,  equipment,  and  the 
lumber  of  persons  on  board. 

The  amount  of  the  displaced  water  is  termed  the  boat's 
*  Duplacement."  and  ia  expressed  as  a  volume  in  cubic  feet,  or 
BB  a  weight  in  tons. 

Thirty-five  cubic  feet  of  displaced  fluid,  if  salt  water,  equals 

CHo  that  if  a  boat  weighed  5  tons,  including  the  full 
it  and  number  of  persons,  the  vrilurae  of  di»place<l  salt 
ist  be  175  cub.  ft. 
''olume,  or  internal  capacity  of  an  open  boat,  referred  to 


I" 
si 

in  8 
^Hnuffl 

llf     as  a 


42  SHIPS'  BOATS 

in  the  Rules  for  Life-saving  Appliances,  when  used  for  obtaining 
the  number  of  persons  a  boat  can  accommodate,  must  not  be 
confused  with  the  volume  of  displacement. 

Buoyancy. — The  support  which  the  boat  secures  from  the 
fluid  in  which  she  is  immersed  comes  from  the  effect  of  pressures 
which  are  being  exerted  at  right  angles  to  the  surface  of  the 
planking,  and  is  termed  buoyancy,  or  in  other  words,  a  boat's 
buoyancy  is  her  "  power  to  float." 

The  point  in  which  all  these  fluid  pressures  are  concentrated, 
or  the  resultant  of  all  the  fluid  pressures  bearing  on  the  ship,  acts 
through  a  point,  and  in  a  direction  vertically  upwards.  This  point 
is  termed  the  '*  Centre  of  Buoyancy''  or  expressed  in  simpler  form, 
it  is  the  centre  of  gravity  of  the  displaced  fluid. 

The  centre  of  buoyancy,  therefore,  depends  upon  the  form 
of  the  underwater  portion  of  the  boat. 

If  a  boat  is  loaded  with  additional  weight,  the  volume  of 
displacement  is  increased,  and  the  distance  of  the  centre  of 
buoyancy  from  L.W.L.  is  consequently  increased. 

In  a  boat  with  a  sharp  rise  of  floor,  the  centre  of  buoyancy 
is  relatively  higher  from  the  keel  than  in  a  boat  with  a  fuller 
underwater  section.  The  finer  form  makes  it  necessary  for  the 
boat  to  float  at  a  deeper  draught,  in  order  to  obtain  sufficient 
displacement  equal  to  its  weight. 

Reference  will  be  made  later  to  this  condition,  as  it  has  an 
important  bearing  on  the  subject. 

If  the  boat  is  inclined  transversely,  the  centre  of  buoyancy 
moves  out  in  the  same  direction  in  which  the  boat  ls  inclined. 

One  of  the  first  conditions  which  must  be  fulfilled  for  a  boat, 
when  floatuig  freely  and  at  rest  in  still  water,  to  remain  in  stable 
equiUbrium  is,  that  the  weight  of  the  water  displaced  must 
equal  the  weight  of  the  boat.  The  following  or  second  condition 
is,  that  the  centre  of  buoyancy  must  be  in  the  same  vertical 
line  as  the  centre  of  gravity. 

Fig.  8  shows  the  relative  positions  of  the  centre  of  gravity 
**  6  "  and  the  centre  of  buoyancy  "  B  ,"  generally  found  in  a 
loaded  open  boat  of  Class  Ia.  The  boat  is  floating  in  stable 
equiUbrium,  with  the  buoyancy  and  weight  acting  in  the  same 
vertical  line. 

It  has  already  been  stated  that  the  weight  of  the  di8placed 
fluid  in  which  the  boat  is  immersed,  must  equal  the  weiglit  of 
the  boat,  ix.  there  must  be  sufficient  buoyancy  to  support  the 
weight  of  the  boat.  If  the  boat  is  damaged  below  the  load 
water-line,  and  water  is  taken  on  board,  then  she  has  to  draw 


FORM,  STABILITY,  STRENGTH,  AND  CAPACITY    43 

upon  the  remaining  intact  space  above  the  water-line,  to  keep  her 
afloat. 

This  intact  volume  is  termed  "  Reserve  Buoyancy,''  and  the 
amount  of  this  volume  has  a  very  direct  bearing  on  influencing 
the  design  of  lifeboats. 

Centre  of  Gravity. — The  position  of  the  centre  of  gravity  is 
entirely  controlled  by  the  distribution  of  material  or  weights, 
and  may  be  described  as  the  point  through  which  the  weight  of 
the  boat,  when  at  rest,  may  be  supposed  to  act  in  a  direction 
vertically  downwards. 

In  Fig.  8  we  see  that  the  upward  supporting  forces  are  acting 
through  the  centre  of  buoyancy,  and  the  downward  force  of  weight 


w 


3 

' 

^ 

c 

■< 

^G 

1. 

A 

i 

rj'-' 

-< 

^B 

_y 

\ 

^ 

w 

Fig.  8. 


is  acting  through  the  centre  of  gravity,  and  both  are  in  the  same 
vertical  line. 

It  is  important  to  remember  that  when  inclining  a  boat  from 
her  upright  position,  and  pro\4ded  no  weights  have  shifted  or 
persons  moved,  the  centre  of  gravity  remains  stationary  at  its 
original  position,  but  the  centre  of  buoyancy  moves  out  in  the 
same  direction  in  which  the  boat  is  inclined,  due  to  the  modified 
form  of  the  underwater  portion  of  the  boat  as  a  result  of 
the  inclination. 

If  weights  or  persons  on  board  are  moved  in  a  longitudinal, 
transverse,  or  vertical  direction,  the  centre  of  gravity  will 
evidently  move  in  the  same  direction  as  the  weights  or  persons 
are  moved. 

Fig.  9  represents  the  result  of  moving  several  persons  from 
one  side  of  the  boat  to  the  other,  in  a  transverse  direction. 
Assuming  the  weight  of  the  persons  moved  as  6  cwts.  (w),  the 


44 


SfflPS'  BOATS 


distance  moved  through,  7  ft.  (d),  and  the  displacement  or 
weight  of  boat  140  cwts.  (W),  the  centre  of  gravity  of  the  boat 
will  move  in  the  same  direction  and  in  a  line  parallel  to  the 
shifted  weight,  by  the  following  amount : — 


wxd 


=  GG' 


6x7 
140" 


42 
140 


•3  ft. 


The  centre  of  gravity  of  a  person  in  a  sitting  position  is  taken 
as  12  in.  above  the  thwart  or  side  bench. 

In  Fig.  9  it  will  be  seen  that  when  the  centre  of  gravity 
moved  to  its  new  position  due  to  the  shift  of  weights  already 
on  board,  the  centre  of  buoyancy  also  moves  to  a  new  position, 


B',  due  to  the  alteration  of  underwater  form,  and  the  boat  is 
brought  to  rest  at  a  certain  incUnation  when  the  buoyancy  and 
weight  are  acting  in  the  same  vertical  line  through  B'  and  G' 
respectively. 

Referring  to  Fig.  10,  a  weight  already  on  board  is  moved 
from  the  thwarts  to  the  lower  cross  seats.  In  this  case  the 
centre  of  gravity  of  the  boat  is  lowered  in  a  vertical  direction,  but 
the  centre  of  buoyancy  retains  its  original  position,  owing  to  no 
alteration  taking  place  in  the  draft  or  underwater  form  of  boat. 

Assuming  the  weight  moved  being  6  cwts.  (w)  and  the  distance 
moved  through,  1*5  ft.  (rf),  then  the  centre  of  gravity  will  be 
lowered  in  a  vertical  direction  by  the  following  amount : — 


wxd 
W 


-GG' 


6  X  1-5 
140 


9 
140 


•0G4  ft. 


FORM.  STABILITY.  STRENOTH.  AND  CAPACITY    45 

1(  a  weight  iii  added  to  tlie  boat,  its  poaitiuii  is  noted  in  relatiou 

to  the  orif^nal  centre  of  gravity  of  boat.     Then,   the  added 

weight  miittipiied  by  it«  dbtance  from  the  centre  of  gravity  and 

divided  by  the  displacement  phis  the  added  weight,  will  give  the 

I   distance  G'  the  new  centre  of  gravity  has  moved,  i.e. — 

W  +  w 
Sitppotting  an  additional  weight  o(  G  cwte.  is  placed  on  the 


1 

w 

C 

-r-^-  -^ 

--4- 

»t 

i 

i- 

..... 

^-M 

W 

r 

^ 

9 

Vy 

Smrts  1'5  ft.  above   the  centre  of   gravity  G,  then  tlie  new 
centre  of  gravity  G'  will  be  raised  062  ft. 

"'X'^,=l=i_l:-'=  1^-062  ft. 

W4-H'      140  +  6      H6 

If  the  weight  is  placed  on  the  lower  seats  r5  ft.  below  the 
centre  of  gravitv  G,  then  the  new  position  of  the  centre  of  gravity 
G'  will  be  062  ft.  lower  than  the  origmal  G. 

In  the  same  way  we  can  ascertain  what  will  be  the  effect  on 
the  centre  of  gravity  if  weights  are  taken  out  of  the  boat,  by 
using  the  same  formula,  except  that  the  weight  taken  out  (wi)  is 
subtracted  fi'oin  the  original  displacement,  thus— 


From  the  foregomg  it  will  be  seen  that  the  centre  of  gravity 
of  a  boat  does  not  move  from  its  original  position  unless  some 
portion  of  the  weight  ahready  on  board  is  shifted,  such  as  tJie 


46  SfflPS'  BOATS 

transference  of  persons  from  one  side  seat  to  the    other,    or 
weights  are  added  or  taken  out  of  the  boat. 

The  position  of  the  centre  of  gravity  is  entirely  dependent  on 
the  distribution  of  weight. 

The  position  of  the  centre  of  buoyancy  is  altered  whenever  a 
change  of  draught  takes  place  or  the  underwater  form  of  the  boat 
changes  as  the.  result  of  the  boat  being  inclined. 

The  relative  positions  of  the  centre  of  gravity  and  the  centre 
of  buoyancy  have  a  very  direct  and  important  bearing  on  a 
boat's  stability. 

To  increase  the  initial  stability  the  weight  added  to  a  boat 
should  be  placed  well  below  the  centre  of  gravity,  or  weights 
already  situated  above  the  centre  of  gravity  must  be  removed 
to  a  position  below.  (See  also  "  Effect  of  internal  water  with  a 
free  surface,"  p.  51.) 

In  this  connection  it  is  very  desirable  to  provide  as  many 
lower  seats  as  the  internal  arrangements  of  the  boat  will 
allow. 

The  thwarts  and  side  benches  are  kept  low  enough  to  be 
consistent  with  the  necessity  to  make  the  oarsmen  feel  comfortable 
and  allow  them  to  pull  with  ease. 

Further  detailed  reference  is  made  to  the  question  of  the 
position  of  the  thwarts  and  their  relation  to  the  stowage  of  the 
watertight  air-cases,  in  Part  IV.,  Section  A. 

Metaeentric  Height. — Reference  now  is  made  to  Fig.  11. 
The  figure  represents  the  midship  section  of  an  open  boat, 
slightly  inclined  from  the  upright  position. 

The  weight  of  the  boat  acts  in  a  vertical  downward  direction 
through  the  centre  of  gravity,  and  the  latter  does  not  move 
from  its  original  position  when  the  boat  is  upright.  The 
portion  between  WL  and  WL',  viz.  WSW,  which  originally 
was  immersed,  has  now  emerged  from  the  water,  and  the  opposite 
action  takes  place  with  the  wedge  portion  LSL'.  The^e  wedge- 
shaped  portions  are  equal,  because  the  volume  of  displacement 
remains  the  same  after  inclination,  as  before.  The  centre  of 
buoyancy,  however,  has  moved  out  in  the  same  direction  as  the 
boat  is  inclined,  and  takes  up  a  new  position  B'.  The  forces  of 
buoyancy  are  now  exerted  in  a  vertical  direction  upwards,  through 
B'.  As  the  weight  of  the  vessel  is  still  acting  through  the  centre 
of  gravity,  and  the  centre  of  gravity  and  the  centre  of  buoyancy 
are  not  in  the  same  vertical  line,  one  of  the  conditions  for  a  boat 
to  float  freely  and  at  rest  in  stable  equilibrium  is  not  being 
fulfilled,  and  it  therefore  shows  that  there  are  two  conflicting 


FORM,   STABILITY,  STRENGTH,  AND   CAPACITY    47 

and  opposite  forces  in  operation,  i.e.  buoyancy  in  one  direction 
and  weight  in  another,  thus  producing  what  is  termed  a  "  couple." 

Where  the  vertical  line  passing  through  the  centre  of  buoyancy 
B',  in  the  inclined  position,  intersects  the  original  vertical  line 
passing  through  B  in  the  upright  position,  at  a  point  M,  this 
point  is  termed  the  Metacentre. 

The  distance  between  G  and  M  (for  small  angles  of  inclination) 
is  the  Metacentric  Height  or  G.M. 

When  the  boat  is  inclined  longitudinally,  the  same  factors 
come  into  operation  as  explained  for  a  boat  inclined  transversely. 
In  the  case  of  a  ship's  boat,  transverse  inclinations  are  more 
easily  produced  and  become  of  more  importance  than  fore-and- 


aft  inclination,  and  attention  will,  therefore,  be  centred  on  this 
condition  throughout  this  section  of  the  treatise. 

When  deahng  with  small  angles  of  inclination  up  to  about 
12°  or  15^,  the  forces  of  buoyancy  acting  along  the  vertical  line 
through  the  centre  of  buoyancy  are  assumed  to  pass  through  the 
metacentre  M,  a  fixed  point;  but  at  larger  angles  of  heel  the 
metacentre  and  the  forces  of  buoyancy  are  not  in  the  same 
vertical  Une. 

Stability  Levers. — If  we  draw  a  line  through  G  at  right 
angles  to  the  vertical  line  passing  through  B',  cutting  it  at  Z,  we 
obtain  the  length  of  the  stability  lever  GZ,  or  arm  of  the  couple, 
which,  when  multiplied  by  W,  the  displacement,  or  the  weight  of 


48  SHIPS'  BOATS 

tlio  boat  with  load,  will  give  iis  the  ''Moment  of  statical 
HtHhilltjiy^  a  force  which  is  in  operation  to  move  the  boat  back 
to  it,s  original  vertical  position  of  rest. 

This  property  or  moment  depends  on  the  design  and  form 
of  the  boat,  and  must  be  equal,  at  all  times,  to  any  external  or 
dynamical  force  tending  to  upset  the  boat. 

If  the  upsetting  force  becomes  greater  than  the  range  of 
statical  stability  the  boat  will  founder. 

The  relative  position  of  G  to  M  has  a  very  important  bearinir 
on  the  length  of  the  stability  lever. 

The  nearer  the  centre  of  gravity  is  brought  to  the  metacentre 
it  follows  that  the  initial  stability  becomes  increasingly  less 
and  when  M  falls  below  G  the  boat  is  unstable,  unless  when 
heeh'ng  over  she  draws  upon  some  reserve  buoyancy  and  remains 
sUible  in  this  inclined  position,  and  on  being  further  inclined  she 
picks  up  a  sl^ibilitv  lever  which  allows  her  to  heel  over  to  a  greater 
angle  in  safety. 

Su(^h  a  ciiso  is  given  in  Fig.  20,  where  the  stability  curve  "  V  " 
is  plotlcHi  out  for  a  pontoon  lifeboat  of  Class  IIb,  which 
f^uiiporarily  took  on  board  a  quantity  of  water,  and  in  the  initial 
inclin«Ml  position  the  metacentre  was  brought  down  below  G 
whi<'h  condition  was  rovei-seil  on  further  inclinations,  imtil  her 
maximum  stability  was  reached  at  about  23"^  of  heel. 

Conditions  of  Equilibrium. — It  will  not  be  out  of  place  at 
lliiH  point  in  the  treatment  of  the  subject  to  make  a  statement 
of  the  three  cimditions  which  must  be  fuliilled  for  a  boat  to  float 
freely  and  at  rest,  in  a  conditiim  of  stable  equihbrium,  viz. : — 

(I)  The  weight  of  the  water  displaced  must  equal  the  total 
wj'i^'ht  tif  the  h<int,  including  e«|uipment  and  the  number  of 
penums  on  board. 

('J)  The  nMitre  of  gravity  of  the  boat  must  be  in  the  same 
vrrlinil  hm*  as  the  centn*  oi  bmnancv. 

(W)  The  rentn*  c»f  gravity  must  be  beK»w  the  metacentre. 

Thr  iiiel  jireni  ric  met  hoil  of  tindinu  the  value  of  a  boat's  stability 
iM  only  iipphtjibh*  up  to  angh»s  of  inclination  of  about  12°  to  15°, 
iiimI  Im'noiuI  Ihesr  angles  other  methods  have  to  be  adopted  to 
rnnhjn  Mm'  leui'lh  of  stabilitv  levers  to  be  accurately  calculated. 

Monirnl  of  Inortla.  The  ili>tance  between  the  centre  of 
iMiMviimv  iind  the  fiMusverse  niotacentie  is  obtained  by  dividing 
Ihr  niMinnit  t»l  nieiliji  o\  the  watoi-plane  ^I),  at  which  the  boat 
iM  liniiiiiiM,  liv  (he  Nohmie  of  ilispl  uement  (\  ).  i.e — 


I 


I 


FORM,  STABILITY.   STRENGTH,  AND  CAPACITY    49 

111  moviiiji  B  weight  iiiim  one  aide  of  tlie  boat  to  the  other. 
or  from  the  thwarts  to  the  lower  seats,  a  moment  waa  brought 
into  operation  which  afiec'ted  the  position  of  the  centre  of  gravity 
of  the  boat,  and  this  weight,  multiplied  by  the  distance  moved, 
was  the  majfnitude  of  the  moment. 

If  we  divide  the  watei-plane  area  into  a  number  of  in- 
finiteeioially  small  parta  and  multiply  each  by  the  square  of 
its  distance  from  a  given  axis,  the  sum  of  all  these  products  yive 
what  is  termed  the  "Moment  of  hierlia"  of  the  water-plane 
about  that  given  axis. 

Just  as  the  disposition  of  weights  affects  the  position  of  the 
centre  of  gi'avity,  ao  the  moment  of  inertia  has  a  direct  bearing 
on  tlie  position  of  the  metacentre. 

If  we  increase  the  area  of  the  water-plane  the  moment  of 
inertia  becomes  larger. 

If  we  increase  the  volume  of  displacement  the  centre  of 
buoyancy  ia  raised  from  the  keel. 

Therefore,  in  a  wall-sided  type  of  boat,  when  floating  at. 
a  deeper  draught  through  the  addition  of  a  number  of  persons 
placed  on  board,  the  area  of  the  water-plane  and  the  moment 
of  inertia  practically  remain  constant,  while  the  centre  of 
buoyancy  rises  nearer  the  metacentre.  There  are  also  other 
conditions  which  come  into  operation  and  mfluence  the  centre 
of  gravity  and,  therefore,  also  the  metacentric  height,  a  phase  of 
the  subject  to  which  further  reference  will  be  made  later  on  in 
this  section. 

Within  the  limits  of  inclination  refeired  to,  the  length  of  the 
stability  lever,  GZ,  can  be  calculated  for  each  consecutive  angle 
ol  heel  by  multiplying  the  metacentric  height,  GM,  by  the  sine 
of  the  angle,  i.e. — 

GZ  =  GM.8infl  (See  Fig.  11.) 

The  length  of  these  level's  are  set  up  t^  a  convenient  scale 
on  &  base  line  representing  the  various  degrees  of  inclination, 
and  a  curve  passing  through  these  spots  will  give  us  a  "  curve 
of  statical  stability"  or  what  is  generally  referred  to  as  the 
"  glabiliiy  curve."  The  true  measure  of  a  boat's  stability  ia  the 
magnitude  of  the  stability  m<iment,  so  that  the  levers  have  to  be 
multiplied  by  the  weight  of  displacement  W. 

When  dealing  with  boats  in  varying  conditions  of "  swamping," 
I.e.  having  on  board  changing  volumes  of  internal  water  with  a 
free  surface,  a  true  comparison  can  only  be  made  by  plotting 
of  stability  moments. 


50  SHIPS'   BOATS 

One  or  two  specinieji  staLility  curves  are  sliown  in  ¥ig.  20, 
The  one  marked  R  repreeents  the  njeasure  of  stability  of  an  open 
boat  of  Class  Ia.  At  0",  in  the  upright  condition  "  A,"  the  boat 
ie  assumed  to  be  floating  in  stable  equilibrium,  i.e.  with  the  centre 
of  buoyancy  and  the  centre  of  gravity  in  the  same  vertical  line. 
Immediately  the  boat  is  inclined  the  centre  of  buoyancy  moves 
out  to  another  position,  while  the  centre  of  gravity  remains  at 
its  original  position,  when  the  stability  lever  GZ  comes  into 
operation.  At  the  position  "  B  "  we  see  that  the  gunwale  is 
brought  to  the  water-level  and  any  further  inclination  would 
allow  the  water  to  enter  and  capsize  the  boat.  The  angle  of 
maximum  stability  is  reached  at  28^.  If  we  were  able  t^  ht  a 
watertight  deck  at  the  gunwales  and  retain  the  original  dimen- 
sions, we  should  probably  find  that  the  maximum  stability  lever 
was  not  increased  by  further  inclinations,  but  the  watertight  deck 
would  have  considerable  effect  on  lengthening  out  the  range  of 
stabihty. 

The  vanishing  angle  of  stabihty  is  reached  when  the  centre 
of  buoyancy  and  the  centre  of  gravity  are  again  in  the  same 
vertical  line  as  indicated  at  "  C."  Any  further  inclination  from 
this  position  would  produce  a  statical  moment  operating  in  the 
same  direction  as  the  dynamic  or  upsetting  force,  t.e.  the  position 
of  Z  would  be  to  the  left  of  G,  and  the  lengths  of  GZ  would  then 
have  to  be  plotted  below  the  base  line. 

Initial  stabili'g  is  the  stability  of  a  boat  in  its  upright  condition. 

Increasing  the  beam  of  a  boat  considerably  iufluencea  the 
initial  stability  and  produces  a  greater  metacentric  height, 
because  the  position  of  M  largely  depends  on  the  moment  of 
inertia  of  the  water-plane. 

It  will  be  noticed  that  pontoon  boata  of  Classes  IIb  and  lie 
and  open  boats  of  Class  IIa  have  a  large  metacentric  height, 
owing  to  special  features  of  their  design. 

Freeboard  has  no  influence  on  the  initial  stability  unless 
there  is  tumble-home  or  flare-out  to  the  sides,  which  will  have 
an  effect  on  the  moment  of  inertia  of  the  water-plane.  It  lias  a 
direct  bearing  on  the  range  of  stability.  The  question  of  free- 
board has  to  be  considered  in  relation  to  the  centre  of  gravity 
of  the  load,  and  whether  the  boat  is  of  the  ojien  or  the  pontoon 
type,  the  latter  possessing  a  watertight  deck ;  open  boats  of  Class 
I  [a  and  pontoon  boats  of  Class  IIo  are  governed  by  a  minimum 
freeboard.  Pontoon  boats  of  Classes  Ic  and  IIb  must  have  a 
minimum  freeboard  which  will  give  them  a  reserve  buoyancy  of 
at  least  35  per  cent. 


I 


I 


FORM,   STAB11,ITY,   STRENGTH,    AND  CAPACITY     51 

Open  boats  of  Classes  Ia  and  Ib  must  have  Butfieient  free- 
board as  will  allow  them  to  bo  inclmed,  under  sail,  with  their 
full  comploDient  of  persona  on  board,  to  a  reasonable  and  safe 
angle  of  heel.  Freeboard  must  be  considered  in  relation  to  the 
centre  of  gravity  of  the  persons  sitting  or  standing.  Persons 
sitting  oil  the  thwarts  of  an  open  boat  of  Olasa  Ia  make  very 
little  diilerence  to  the  centre  of  gravity  of  the  fully-loaded  boat 
when  they  stand  on  the  bottom  boards,  but  in  boats  of  Classes 
Ic,  IIa,  IIb  and  IIo  it  is  imperative,  ia  their  own  intereata,  for 
persons  to  retain  their  seats  in  oider  to  maintain  the  maximum 
stability  qualities  of  the  boat. 

As  previously  explained  when  dealing  with  the  question  of 
form,  it  is  essential  inopen  boats  of  Classes  I  A,  Ib,  and  III.  to  work 
to  a  suitable  breadth,  with  a  reasonable  freeboard,  and  keep  the 
weight  down  in  the  boat  as  low  as  possible.  The  inclination  oi 
the  stability  curve  to  the  base  line  gives  us  a  vei^'  good  idea 
of  the  initial  stability  of  a  boat,  the  more  obtuse  this  angle 
becomes  the  greater  ia  tiie  initial  stability ;  so  that  we  notice 
with  the  pontoon  lileboats  and  open  boat.8  with  collapsible 
bulwarks,  that  their  stability  curves  rise,  from  0",  above  the 
curves  of  an  open  boat  of  (.'lass  Ia,  owing  to  their  greater  meta- 
centric height. 

The  condition  "  C  "  in  Fig.  20  was  only  inserted  for  the 
purpose  of  illustration,  but  it  is  reasonable  to  imagine  that  such  u 
boat  will  bo  of  great  value  as  a  life-saving  apphance.  The  depth, 
of  course,  woidd  have  to  be  increased  for  the  satisfactory  accom- 
modation of  the  persons  to  be  carried.  Boats  that  incline  to  large 
angles  would  have  the  effect  of  pitching  the  occupants  off  the  seats 
and  thus  bring  mU>  operation  a  moment  tending  to  capsize. 

However,  such  a  boat  has  been  recommended  by  the  Boat* 
Bud  Davits  Committee,  and  with  these  features  in  view  the 
Welin  Davit  and  Engineering  Co,,  Ltd.,  have  designed  special 
boats,  illustrations  of  which  are  shown  in  Figs,  130-132. 

EReet  of  Internal  Water  with  a  Free  Surlace. — The  efiect  of 
free  water  in  a  boat  on  the  stabiUty  is  of  very  great  importance, 
particndarly  in  the  Open  Classes.  With  the  pontoon  lifeboats 
provision  is  made  for  quickly  clearing  water  taken  over  the 
gunwale  on  to  the  deck,  by  fitting  special  drain  valves. 

Very  instructive  papers  were  road  before  the  Institution  of 
Maval  Architects  in  1912  and  the  Institution  of  Engineers  and  Ship- 
builders in  Scotland  in  1913  by  the  late  Mr.  A.  Cannon,  R.C.N.C., 
H.I.N,A.,  giving  the  results  of  his  investigations  regarding  the 
effect  of  an  internal  free  fluid  upon  the  initial  stabiUty  and 


1 


52  SHIPS'    BOATS  I 

stability  at  large  angles,  in  ahijra  of  various  forms.  Mr.  Cannon  I 
was  good  enough  to  allow  the  writer  full  opportunity  to  use  I 
these  papers  for  publication  in  the  present  treatise,  as  the  subject  I 
is  80  closely  associated  with,  and  has  a  direct  hearing  on,  the  I 
design  and  construction  of  ships'  boats.  I 

Watertight  air-cases  are  fitted  in  a  boat  to  increase  the  I 
maximum  righting  moment,  by  I'edueing  the  moment  of  inertJa  I 
of  the  free  surface  of  water,  and  also  to  provide  a  reserve  of  I 
buoyancy  should  the  boat  become  flooded.  I 

When  water  is  first  taken  over  the  gunwale  into  an  open  I 
boat  the  added  weight  is  below  the  centre  of  gravity,  and  for  I 
tjie  purpose  of  a  basis  for  argument,  we  will  suppose  this  added  I 
weight  of  water  to  be  fixed,  tie  effect  of  which  will  be  to  increase  1 
the  initial  stabihty  by  lowering  the  centre  of  gravity  of  the  J 
boat.  J 

Considering  the  water  as  free,  the  metacentre  is  immediately  J 

influenced  by  the  value  „,  i.e.  the  moment  of  inertia  of  the  free   ] 

surface  of  water,  divided  by  the  volume  of  displacement  of  the  I 
boat.  As  the  amount  of  water  increases  in  the  boat,  the  moment  of  ] 
inertia  (i)  practically  remains  constant,  being  limited  between  j 
the  vertical  sides  of  the  buoyancy  air-casea.  The  weight  added  j 
below  the  C.G.  increaaea  and  tends  to  lower  the  latter. 

In  the  first  place,  there  is  a  reduction  in  the  metacentric 
height,  but  eventually,  with  a  certain  incre-ased  quantity  of 
internal  water,  which  has  the  e£Eect  of  lowering  the  centre  of 
gravity,  the  original  metacentric  height  is  recovered  and  as 
further  quantities  of  water  are  added  it  increases  until  it  reaches  1 
a  maximum  height,  when  the  water-level  inside  the  boat  is  the  ] 
same  as. the  water-level  outside. 

It  does  not  always  follow  that  because  a  weight  is  placed 
below  the  centre  of  gravity  the  metacentric  height  is  necessarily 
increased,  because  an  account  must  be  taken  of  the  metacentre, 
which  has  changed  its  position  with  the  increase  of  draught. 

As  the  eSect  of  internal  water  with  free  surface  increases  the  I 
initial  st^ability  uf  a  boat  between  certain  points,  its  eSect  on  the  I 
curve  of  stability  and  the  range  apparently  grows  less,  so  that  J 
in  the  condition  already  referred  to,  when  the  height  of  the  watoi  J 
inside  is  the  same  as  that  outside  the  boat,  giving  maximum  I 
initial  stability,  the  statical  stabihty  at  finite  angles  is  at  i 
minimum. 

Initial  Stability. — The  following  deductions  are  taken  from-V 
Mr.  Cannon's  investigations  on  the  effect  uf  an  internal  freofl 


FORM,   STABILITY,  STRENGTH,  AND  CAPACITY    53 

fluid  on  the  initial  stability  of  a  vessel,  and  made  applicable  to 
the  conditions  of  a  ship's  boat : — 

(a)  Consider  the  vxxter  (is  an  added  weight.     Referring  to 
Fig.  12, 

Let  V  =  the  volume  of  displacement  before  the  free  water 

enters  the  boat  over  the  gunwale. 
Let  V  =  the  volume  of  added  water. 
Let  6  =3  the  vertical  centre  of  gravity  of  added  water. 
Let  i  =  the  moment  of  inertia  of  the  free  surface  of  the 

added  water,  about  its  longitudinal  middle  line. 


FiQ.  12. 


For  small  angles  of  heel  the  weight  of  the  free  water  will  act 
through  the  point  m,  where 

i 


bm  == 


V 


Thus  the  centre  of  gravity  of  the  boat  virtually  drops  from  a 
point  6  to  G',  so  that 


(V  +  t;)GG'  =  vGm 


therefore 


V 


GG'  =^^  ^,  -  Gm 

V  + 1; 


If  the  surface  of  the  internal  fluid  had  been  fixed  the  drop  of  G 
would  have  been 

V 


Y+v 


G6 


54 


SHIPS'   BOATS 


and,  therefore,  the  loss  of  metacentric  height  due  to  freedom  of 
surface 

V     ,  i 

\  -\-v  V  +  V 


(G6  -  Gm) 
bm 


This  refers  to  the  metacentric  height  of  a  vessel  of  volume 
V  +  v,  therefore,  the  loss  of  stability  at  a  small  angle 


Fio.  13. 


(b)  Consider  the  water  as  a  loss  of  buoyancy.  Referring  to 
Fig.  13, 

Let  V  be  the  intact  volume  of  a  boat. 

Let  B'  be  the  centre  of  buoyancy  of  this  intact  volume. 

Find  a  point  M'  where  B'M'  =    . 

Where  I  is  the  moment  of  inertia  of  the  water-plane  WL 
about  its  longitudinal  middle  line. 

Then  M'  would  be  the  metacentre  if  the  surface  of  the  internal 
fluid  were  fixed,  and  the  restoring  moment  at  a  small  angle  0, 
would  be 

V  .  GM' .  e 


FORM,  STABILITY,   STRENGTH,  AND  CAPACITY    55 

Owing  to  the  freedom  of  the  surface,  this  exerts  an  upsetting 
couple 

ie 

and,  therefore,  if  6M  is  the  virtual  metacentric  height,  the 
restoring  couple  at  0  is 

V .  GM .  0  =  V .  Gwe  -  ie 

therefore  GM'  -  GM  =  ^ 

In  the  first  method  (a)  we  are  dealing  with  the  change  in  the 
metacentric  height  in  the  volume  Y  -{-v,  whereas  in  the  second 
method  (6)  we  are  dealing  with  a  change  in  the  metacentric  height 
in  the  volume  V.  In  each  case  the  loss  in  the  initial  stability 
couple  is 

iS 

(c)  The  silbject  was  also  treated  from  quite  a  different  stand- 
point and  based  upon  the  application  of  a  theorem  evolved  by 
an  eminent  French  naval  architect  and  known  as  '*  Leclert's 
Theorem,"  which  is  an  expression  for  the  radius  of  curvature  of 
the  curve  of  flotation. 

A  curve  of  flotation  is  the  locus  of  the  centre  of  gravity  of  , 
the  water-plane ;  in  other  words,  it  is  a  surface  generated  by  a 
line  drawn  through  the  various  positions  of  the  centre  of  gravity 
of  the  water-plane  as  the  boat  is  inclined  at  a  constant  displace- 
ment. A  property  of  this  curve  is  that  the  water-line  at  any 
point  is  always  a  tangent  to  it.  The  value  of  the  radius  of 
curvature  is  given  by 

^^     rfV 

where  in  Fig.  14  W'L'  is  a  water-line  parallel  to  and  very  near 
WL,  cutting  off  a  volume  V  +  ^  and  having  I  +  rfl  as  its  trans- 
verse moment  of  inertia. 

Let  g^  be  the  centre  of  gravity  of  the  small  layer  of  buoyancy 
between  \VL  and  W'L'. 

Let  wl  and  w'l'  be  the  water-line  when  the  boat  is  inclined  at 
a  very  small  angle  from  the  upright,  and  let  ^'  be  the  centre  of 
gravity  of  the  layer  in  this  condition. 

In  the  upright  position  the  buoyancy  of  the  layer  acts  in  a 
vertical  direction  through  (p\  and  in  the  inclined  condition  it 
acts  in  a  vertical  direction  through  g\ 

The  two  lines  of  action  will  meet  at  0. 


56 


SHIPS'   BOATS 


Then  0  becomes  the  metacentre  of  the  small  layer  of  buoyancy. 

When  the  layer  is  very  small  g^  and  g'  become  consecutive 
centres  of  flotation.  Og^  and  0/  are  then  lines  through  consecu- 
tive centres  of  flotation,  perpendicular  to  consecutive  tangents 
to  the  curve  of  flotation.  0  is  therefore  the  centre  of  curvature 
of  the  curve  of  flotation  so  that  "  the  centre  of  curvature  of  the 
curve  of  flotation  is  the  metacentre  of  the  small  layer  of  buoyancy  at 
the  water-line'^ 

The  practical  value  of  these  considerations  can  now  be  applied 
to  the  case  of  an  ordinary  open  ship's  boat. 

In  Fig.  15  let  G  be  the  centre  of  gravity  of  a  boat  loaded  with 
a  number  of  persons  seated  on  the  side  benches  and  thwarts. 


-wt  — 


r 


__ [\ -.-."._-."".":;..  J5-V 

rr's— ■  T   ^Ti  ^— ^— 


FiQ.   14. 

Supposing  a  weight  of  moderate  amount  w  is  placed  on  the 
lower  seats  at  P. 

Consider  the  stability  at  a  small  angle  $.  The  placing  of  w 
on  board  causes  a  small  laver  of  buovancy  to  be  added  at  the 
water-line  of  displacement  u\ 

Thus  we  have  :  W  the  weight  of  the  boat  acting  vertically 
downwards  through  G  and  w  the  added  weight  acting  vertically 
downwards  through  P. 

The  buoyancy  V  is  acting  vertically  upwards  through  M.  The 
metacentre  and  the  added  layer  of  buoyancy  rfV  is  acting 
vertically  upwards  through  0,  the  centre  of  curvature  of  the 
curve  of  flotation. 

The  effect  of  adding  a  small  weight  at  the  position  shown, 
will  be  a  restoring  couple  of  moment «/?  X  OP  sin  Q. 

(ci)  In  a  fully-loaded  lifeboat,  owing  to  its  wall-sidedness,  in 


FORM,  STABILITY,   STRENGTH,  AND  CAPACITY    57 

the  neighbourhood  of  the  load  water-line  and  the  gunwale,  d\  ia 
practically  zero,  so  that 

which  brings  the  actual  position  of  0  in  the  water-line. 

(C2)  In  an  open  boat  of  Class  I.,  floating  in  the  Ught  condition 

and  having  a  sharp  rise  in  the  underwater  form,  -^  will  be  a 

large  quantity  and  0  would  be  necessarily  high,  consequently 


Fio.   15. 


any  weight  placed  on  board  below  0  will  increase  the  moment 
ol  stability. 

(C3)  If  there  is  tumble-home  in  the  vicinity  of  the  load 
water-line  and  a  small  weight  is  added  to  the  boat,  R  will  become 
a  negative  quantity,  because  the  moment  of  inertia  of  the  water- 
plane  decreases  as  V  the  volume  of  displacement  increases.  In 
this  case  the  position  of  0  will  be  below  the  load  water-line. 

Thus,  in  the  case  of  (ci),  if  a  weight  is  added  above  the  water- 
line  it  will  diminish  the  moment  of  stabiUty. 

If  added  at  the  water-line,  there  is  no  change  in  the  moment 
of  stability. 

If  added  below  the  water-line,  the  moment  of  stability  Is 
increased. 


58  SfflPS'  BOATS 

An  interesting  feature  of  this  treatment  of  the  subject  is, 
that  the  position  of  0  may  be  below  the  centre  of  gravity  of  the 
boat,  and  by  adding  a  moderate  weight  to  the  boat  above  O, 
but  below  6,  the  effect  will  be  to  reduce  the  moment  of  stability, 
which  contradicts  the  usual  but  mistaken  theory,  that  the 
addition  of  a  weight,  if  added  below  the  centre  of  gravity,  always 
has  the  necessary  effect  of  increasing  the  stability.  ThiB  latter 
reasoning  does  not  take  into  consideration  that,  with  an  increase 
of  draught,  the  metacentre  usually  changes  in  position,  and  that 
the  initial  stability  depends  on  the  relative  positions  of  the  centre 
of  gravity  and  the  metacentre. 

Applying  the  same  principle  to  the  case  of  an  open  boat 
having  a  quantity  of  internal  water  with  a  free  surface,  let  us 

ur 

r  ■    \i 

L. f^ 


follow  out  the  effect  on  the  initial  stability  by  continually  adding 
to  this  internal  water. 

Reference  is  made  to  Fig.  16. 

In  the  same  way  that  0  was  shown  to  be  the  metacentre  of  a 
small  layer  of  buoyancy,  so  0',  the  centre  of  curvature  of  the 
curve  of  the  centres  of  gravity  of  the  free  surface  of  the  internal 
fluid,  can  be  shown  to  be  the  virtual  centre  of  gravity  for  a  small 
addition  of  fluid. 

Supposing  a  small  weight  of  fluid  w  be  added,  then  at  any 
small  inclination,  it  will  act  through  0'  and  the  small  addition 
of  buoyancy  will  act  through  0. 

The  relative  positions  of  0  and  0'  will  determine  the  effect 
on  the  moment  of  stability. 


FORM,   STABILITY,  STRENGTH,  AND   CAPACITY    59 

If  0'  is  below  0,  the  stability  will  be  increased  until,  when  the 
two  points  coincide,  the  initial  stability  is  at  its  maximum. 

As  previously  explained,  the  position  of  0  in  a  loaded  boat 
would  be  usually  found  in  the  L. W.L.  Therefore,  we  arrive  at  the 
conclusion  that  the  initial  stability  will  be  at  its  maximum  when  the 
level  of  the  water  inside  the  boat  is  the  same  as  that  on  the  outside. 

The  study  of  geometrical  stability  has  a  great  fascination  to 
students  of  naval  architecture,  and  the  writer  has  been  prompted 
to  refer  to  the  subject  at  greater  length  than  was  originally 
intended.  It  is  considered,  however,  that  the  result  of  Mr. 
Cannon's  investigations  has  a  very  direct  bearing  on  one  of  the 
most  important  phases  of  the  subject  as  it  relates  to  ships'  boats. 
The  Uberty  has  therefore  been  t'aken  to  give  more  than  an  outUne 
reference  to  these  deductions. 

The  form  of  boats  must  be  considered  so  as  to  obtain  the 
greatest  values  for  initial  stability,  but  as  already  stated,  it  is 
just  as  essential  to  investigate  the  maximum  range  of  stability, 
and  the  effect  of  internal  water  with  a  free  surface,  on  the 
stability,  of  boats,  at  large  angles  of  inclination. 

Stability  at  Large  Angles  of  Inclination. — Referring  to  Fig.  17, 
let  W'L'  be  the  inclined  water-line  of  the  boat,  w'V  the  level 

Vi\ur 


of  the  internal  water  at  this  inclination,  and  WL  the  water-line 
of  the  boat  in  the  upright  condition. 

B  is  the  centre  of  buoyancy  of  the  water  in  the  uprigjht 
condition. 


60  SHIPS'   BOATS 

6  is  the  centre  of  gravity  of  the  boat  with  no  free  water. 
First  assume  the  internal  water  to  be  solid.     Then  the  C.6. 
of  the  boat  and  water  is  at  G',  so  that 

( W  +  w)KG'  =  W .  KG  +  w^ .  K6 

W  being  the  weight  of  the  boat ;  w  being  the  weight  of  internal 
water. 

Then,  if  B  is  the  centre  of  buoyancy  at  the  water-line  WL, 
and  if  KN  is  drawn  parallel  to  WL,  the  value  of  the  righting 
lever  G'Z,  is  given  by 

G'Z  =  KN  -  KG'  sin  6 

When  at  this  inclination,  assume  the  water  to  become  liquid 
again.  It  will  then  take  up  the  position  indicated  by  w'l\  Let 
b'  be  its  C.G.  in  this  condition. 

Draw  Vr  perpendicular  to  w'V  and  br  parallel  to  w'V, 

Then  a  weight  w  has  been  transferred  through  a  distance 
br  parallel  to  G'Z. 

Hence  the  loss  of  G'Z  due  to  this 

w  - 

Xbr 


W  +  w 

If  b'r  cuts  KN  at  n,  then  br=Kn  —  Kb  sin  0,  therefore  the 
loss  of  G'Z  due  to  freedom  of  surface 

^      (Kn  -  K6  sin  0) 


W  +  w 

Thus  in  order  to  obtain  the  GZ  curve  for  internal  free  water, 
first  determine  the  values  of  KN  and  Kn  in  terms  of  the  dis- 
placement of  the  boat  and  weights  of  free  water  respectively  at 
various  angles  of  inclination,  and  plot  these  in  the  usual  manner 
as  cross  curves  of  stability. 

Therefore  the  effect  of  internal  water,  having  a  free  surface, 
on  the  value  of  a  boat  as  a  life-saving  appliance,  at  moderate  to 
large  angles  of  inclination,  is  to  considerably  reduce  the  moment 
of  statical  stability. 

In  pontoon  lifeboats  of  Classes  Ic,  IIb,  and  lie,  water  taken 
over  the  gunwale  on  to  the  deck  would  have  a  greater  effect  on 
the  metacentric  height  than  in  an  open  lifeboat,  if  it  were  not  for 
the  special  provision  made  to  meet  the  emergency  by  fitting 
non-return  drain  valves  in  the  deck.  The  special  feature  in  the 
design  of  these  three  types  of  boat  is  that  when  water  is  taken  on 
board,  it  is  almost  immediately  cleared  by  the  relief  valves,  which 


I 


FORM,   STABILITY,  STRENGTH,  jVND   C.U'ACITY     lil 

automatically  dischargu.  the  surface  wat«r  on  deck  very  rapidly 
through  tubes  titt«d  between  the  deck  and  double  akin,  and  at 
the  same  time  prevent  water  cetuminf;  through  the  tubes  on  deck. 
In  the  case  of  open  lifeboats  of  Class&s  Ia.  IIb,  and  Ha,  water 
taken  on  board  over  the  gunwale  from  heavy  seaa  increase  in 
volume  unless  proper  means  are  provided  for  discharging  the  same. 
The  wat«r  thus  taken  on  board  is  situated  at  a  greater  distance 
from  the  centre  of  gravity  of  the  boat  than  in  the  case  of  the 
pontoon  lifeboats,  but  it  seems  very  essential  that  some  better 
provision  should  be  made  in  open  boats,  say  over  20  ft.  in  length, 
than  the  usual  baler,  by  fitting  a  small  mechanical  hand  pump 
at  each  end  of  the  boat,  which  could  adequately  cope  with  all 
reasonable  emergencies. 

The  absence  of  buoyancy  air-cases  in  a  boat  of  Class  111. 
seriously  reduces  its  efficiency  as  a  life-saving  appliance  in  vessels 
engaged  in  the  Foreign  Trade,  but  one  has  also  to  consider  that 
this  type  of  boat  is  only  carried  in  cargo  vessels,  where  boat 
accommodation  is  provided  for  the  total  number  of  crew,  on 
each  side  of  the  ship.  However,  this  type  of  boat,  owing  to  its 
handiness  in  management  and  quick  facilities  for  laimching,  is 
often  used  when  the  larger  lifeboats  are  kept  in  their  stowing 
chocks. 

A  comparison  of  the  various  featiires  connected  with  the 
three  main  claAses  of  ships'  boats  is  given  in  Table  XI.  (p.  62), 

A  full  detailed  specification  must  be  submitted  to  the  Board 
of  Trade  before  construction  takes  place  on  boats  of  Classes  lo, 
IIa,  FIb,  and  lie,  and  when  completed  the  various  types  of  boats 
have  to  undergo  stability  and  other  tests  before  a  recognised 
standard  of  construction  and  dimensions  can  be  followed.  A 
satisfactory  condition  of  stability  is,  therefore,  practically  assured 
with  these  tj-pes  of  boats. 

In  the  case  of  open  boats,  if  tlie  various  factors  referred  to, 
when  discussing  the  question  of  form,  are  recognit5ed,  a  reasonable 
measure  of  stability  is  assured  in  everj'  condition  of  service. 
These  guiding  factors,  based  on  the  results  of  stability  tests,  are 
given  in  a  convenient  form  for  the  information  of  the  boatbuilders, 
to  prevent  the  necessity  of  woi'king  out  extended  calculations. 

Investigations  of  the  Departmental  Committee  on  Boats  and 
Davits. — Before  the  subject  of  stability  is  brought  to  a  conclusion, 
reference  will  briefly  be  made  to  some  of  the  investigations  of  the 
Departmental  Committee  on  Boats  and  Davits,  the  Report  of 
which  is  published  by  His  Majesty's  Stationery  Office,  and 
be  purchased  through  any  bookseller. 


1 


62 


SHIPS'   BOATS 


TABLE  XI. 

COMPABISON    BETWEEN   CLASSES   OF   BoATS,   WITH  FULL   LOAD. 


Buoyancy  . 


Stability    (bul- 
warks intact) 


Stability  (parti- 
ally swamped) 


Open  lifeboat,  Class 
Ia. 


Pontoon  lifeboats, 
Classes  lo,  llB,  and  lie. 


Floats  witb  full  load  i  Floats  with  full  load 


when  swamjied  to 
gunwale. 


StabUity(fullof 
water  and  at 
point  of  foun- 
dering 


Possesses  good  in- 
itial stability. 

Range  of  stability 
to  about  28°  to  30^ 

Moderately  stiff, 
and  has  stability 
until  gunwale  goes 
below  water-level. 

(See  Curve  R  in 
Fig.  20.) 

Possesses  good  in- 
itial stability. 

Range  of  stability 
depends  on  free- 
board; varies  be- 
tween 16''  and  20°. 

Has  righting  mo- 
ment untilgunwalc 
goes  below  water- 
level. 

(See  Curve  R'  in 
Fig.  20.) 

Possesses  very  little 
initial  stability 
and  practically  no 
range. 

There  is  a  chance* 
of  righting  if  occu- 
pants "  duck  un- 
der." 


oven  when  bul- 
wark is  le^kking 
and  so  long  as  the 
permanent  struc- 
ture is  intact. 

Range  of  stability 
toabout29°to32*. 

Stiff  boat,  and  has 
stability  until  gun- 
wale goes  below 
water-level. 

(See  Curve  T  in 
Fig.  20.) 


Ts  unstable  in  up- 
right position  with  | 
water  on  deck,  but 
with  good  relief ! 
valves  cannot  re- 
main long  partially 
swamped.  j 

Has  a  small   range 
of  stability.  i 

(See    Curve    S    in 
Fig.  20.)  I 


No  stability  until , 
water  is  spilled  | 
over  the  gunwale,  j 

There  is  a  chance  | 
of  righting  if  occu- , 
pants    are    not| 
throwTi  overboard 
belore  the  treeing 
valves    clear    the 
deck. 


Open  lifeboat,  Clabs 

IlA. 


Has  sufficient  buoy- 
ancy to  floai)  with 
full  load,  provided 
permanent  struc- 
ture remains  in- 
tact. 

Should  have  a  range 
of  stability  to  about 
28°  to  32°,  provided 
bulwarks  remain 
intact. 

Has  stability  until 
gunwale  eoes  be- 
low water-level. 


Fairly  good  range 
of  stability,  de- 
pending on  free- 
board and  bul- 
warks remaining 
intact. 

Is  stable  in  upright 
position. 

Water  has  to  be 
baled  out,  same  as 
Class  Ia. 


Similar  to  Class  Ia 
Lifeboats. 


This  Committee  was  appointed  to  advise  the  Board  of  Trade, 
in  the  interest  of  safetv  of  life  at  sea,  as  to  what  are  the  most 
efficient  arrangements  for  stowing  and  launching  boats,  and 
several  other  vital  questions  aflFecting  life-sa\nng  appliances. 

Arising  out  of  the  terms  of  reference,  the  Committee  made 


(FORM,  STABILITY,  STKENCiTH,  AND  CAPACITY  63 
eertain  inve^stigations  into  the  question  of  capacity  and  stability 
of  boats,  and  attached  to  their  Repoit  are  a  number  of  diagrams 
which  show  the  results  of  test8  upon  different  forms  of  boats,  in 
the  light,  loaded,  and  swamped  cunditionu. 
It  was  rightly  pointed  out  tliat  several  boats  were  tested 
afloat,  with  the  intended  number  iif  pci-aona  on  board,  but  these 
tests  could  only  bo  carried  out  in  still  water,  which  was  not  con- 
sidired  sufBcient  to  determine  the  fitness  of  a  boat  to  cany, 

I  in  a  seaway,  the  allotted  number  of  persotis. 
The  investigations  were  continued  in  order  to  ascertain  the 
measure  of  stability  of   each  boat,  and  the  influence  of  form 
upon  capacity  and  stability. 
Five  different  open  lifeboatt)  of  Class  Ia  were  dealt  with,  four 
of  them  being  the  same  dimensions,  but  each  having  a  different 
characteristic  in  design. 
Two  decked,  and  one  partially  decked,  boats  were  utilised  for 
the  purpose  of  securing  data  for  comparison. 
Reference  is  made  to  the  comparative  tests  carried  out  on 
two  of  the  open  lifeboats,  named  herein  as  A  and  C,  and  only  as 
they  aSect  the  subject  of  initial  stability  and  maximum  righting 
moment. 

The  dimensions  were  as  follows  :  — 
Length,  28  ft.,  breadth,  8  ft.  6  in.,  and  depth,  3  ft.  6  in. 
Coefficient  of  Form  : — A=  "694  and  C  =  "65.     Type  "  C  "  boat 
ssed  a  much  sharper  rise  of  floor  than  the  Type  "  A  "  boat, 
1  the  comparative  half-midship  sections  are  shown  in  Fig.  18. 
In  order  to  ascertain  the  conditions  which  would  give  equal 
Lability  to  boats  having  the  same  dimensions,  but  of  different 
libims,  the  alternatives  of  initial  motacentric  height  and  free- 
Kbo&rd  were  tried,  but,  ultimately,  both  were  abandoned  in  favour 
W>f  maximum  righting  moment  as  a  measure,  because  reserve 
■.Inioyancy  and  freeboard  are  both  factors  which  Influence  the 
e  of  righting  moments. 
A  compaiison  of  certain  particulars  in  the  two  f^^pes  of  boats 
B  gtveu  in  Table  XII. 

TABLE  SII. 


^t»«lrflx»t 

DlDMOllOD*. 

Capacity  Id  cubic  Iwt. 

Ccwffl<>Iant  ol 

LxBxDx-B. 

Stirling'.  Eule. 

(ono. 

|(a>HiA) . 

88-(J'x9-6'x3-6' 
2IC(l'x8-B'x3-5' 

BOO 

577 

■6H 
■65 

J 


SHIPS-  BOATS 


Typeofbort. 

Utaplgoi-      DnilEht 
mant  !□    ftom  bottom 
toni.           ol  kiisl. 

loi)irfl»el. 

FlMbOUd. 

"ffl?^ 

A  («l  lisht  draught)  . 
C  (al  light  dnvi^ht)  . 
A  (at  luad  draught)  . 
C  (al  I(M<1  draught)   . 

2'23 
203 
5-3tt 
5-1(1 

1:9: 

I'  Ill- 
s'  2i' 

r  10" 

2'  tr 
2'  r 

2' 01' 
I'BK 

6-18' 
34' 

1-or 

2-0' 

n  board}.     Load  Dnugiil  (50  [wnoiu  oa  I 


The  metacentric  dia^^ams  have  been  drawn  for  each  boat 
and  are  shown  in  Fig.  19, 

It  must  be  borne  in  mind  that  the  weight  per  person  used 
during  these  tests  was  140  lbs.,  as  compared  with  165  Iba,  in  1 
accordance  with  the  Life-saving  A  ppliancea  Rules  now  in  operation, 
but  in  view  of  the  provbion  of  lower  cross-seats  in  boats  of  recent 
wjnatruction,  which  lowers  the  centre  of  gravity  and  increases 
the  metacentric  height,  the  comparison  will  be  useful  and  s 
ciently  accurate  to  show  the  various  factors  which  come  into 
operation  in  a  boat  with  variable  conditions  of  loading  and  in- 
clination. 

In  order  to  obtain  the  maximum  righting  moment  the  boats* 
were  loaded  with  weights,  equal  to  a  specified  number  of  persons 
at  140  lbs.  per  pereoQ.  Weight'*  were  then  moved  from  the 
middle  line  t«  the  gunwale,  to  produce  inclination,  and  it  waa 
found  that  in  the  "C'"'  boat  the  upsetting  moment  gradually 
increased  aa  the  additional  weight  was  placed  on  board,  until  it 
reached  a  maximum,  with  weights  equal  to  55  pej-sons,  of  2-61  ft.- 
tona.  The  maximum  upsetting  moment  for  the  "  A  "  boat  was 
reached  when  weights  equal  to  50  persons  had  been  added, 
giving  '2'76  ft. -tons,  and  when  additional  weights  were  placed  on 
board  the  stability  moment  decreased  until  with  56  persons  on 
board  it  amounted  to  2-69  ft. -tons. 

In  the  upright  condition  it  will  be  noticed  that  the  "  A  "  boat 
possessed  a  greater  metacentric  heiglit  when  floating  at  tJie  light 
wat«r-line  than  the  "  C  "  boat,  but  with  the  weight  of  50  persons 
on  board,  the  "  C  "  boat  has  '33  ft.  greater  metacentric  height 
than  "A." 

When  loaded  with  weights  equal  to  55  persons,  the  range  of 
etabihty  for  tlie  "  A  "  boat  waa  281°  and  that  for  the  "  C  "  1 
was  27i°. 


FORM,  STABILITY.  STRENGTH,  AND  CAPACITY    65 


scALc  or  Tons  D/spiAceMc/rr 


-1-    -— -' — " 

// 

\ 

•..'iis^ 

// 

\     si!^' 

-^^ 

,  ^^- 

l^' 

""'S;*- 

tr- 

"A" 

— — ^^              1 

/ 

\           ^ 

— ^ 

,/ 

,  s^^fff-E.?:i!< 

.-jLfMAiSMMfln: 

/'    ^ 

.......  ■) 

/^^   "•■■ 

^-ij<.«/.«ff.tirt*t. 

/ 

Fio.   19, 


66 


SHIPS"  BOATS 


When  loaded  with  weights  equal  to  50  persona,  which  approxi- 
mates nearer  to  the  number  carried  under  service  conditions,  the 
angle  of  maximum  stabihty  for  the  "  A  "  boat  was  29J°  and  that 
foE  the  "  C  "  boat  was  28°. 

In  the  loaded  condition  the  "  A  "  boat  possessed  SJ  in.  more 
freeboard  than  the  "  C  "  boat. 

A  further  experiment  was  undertaken  to  ascertain  the  qualities 
of  the  "  A  "  boat  when  flooded  with  water,  by  withdrawing  the 
plugs  from  the  drain  holes  and  allowing  water  to  enter,  until  it 
found  ite  level  with  the  water  outside,  when  it  was  found  that 
3'9  ton-s  had  been  admitted.  The  plugs  were  re-inserted  and 
ballast  was  added  to  'the  boat  ef}ual  to  the  full  load  and  placed 
as  nearly  as  possible  at  the  centre  of  gravity  of  the  persona  to  be 
carried.  When  G  cwta.  had  been  transferred  from  the  centre  line 
to  the  centre  of  the  side  seats,  the  boat  heeled  through  an  angle  of 
14|°,  and  after  another  half-hundredweight  had  been  shifted  water 
flowed  over  the  gunwale.  The  masimuni  angle  of  stability  was 
16°  and  in  this  position  the  righting  lever  was  found  to  be 
V5  in.,  the  righting  moment  just  balancing  the  upsetting 
moment. 

In  the  unawamped  condition  it  requbed  13'D  cwts.  to  bring 
the  gunwale  to  the  level  of  the  water  outside  the  boat,  and  the 
righting  lever  was  then  C'i  in. 

The  difference  in  displacement  at  the  load  and  hght  draughts, 
for  both  the  "  A  "  and  "  C  "  boats,  should  be  exactly  the  same, 
being  the  weight  of  the  number  of  persons  placed  on  board. 

Investigations  were  also  made  into  the  stability  of  decked 
and  partially  decked  lifeboats  in  a  similar  way  to  that  adopted 
for  open  lifeboats.  The  full  lines  of  these  boats  and  the  low 
centre  of  gravity  of  their  complement  of  persona,  give  them  a 
high  initial  stability  combined  with  a  long  range,  provided  that 
the  collapsible  bulwarks  remain  watertight. 

The  centre  of  gravity  of  a  loaded  boat  is  considerably  in- 
fluenced by  persona  sta-nding  on  the  deck  of  a  pontoon  lifeboat. 
It  is  essential  for  persons  to  retain  their'aeats  in  these  types  of 
boats. 

The  details  aasociat«l  with  the  various  designs  of  decked  and 
partially  decked  boats  are  dealt  with  in  Sections  D  and  E  of 
Part  IV. 

StablU^  Curves.— A  number  of  typical  statical  stabihty 
curves  are  shown  in  Fig.  20. 

For  the  purpose  of  comparison,  it  is  necessary  to  plot  the 
curves  for  the  moment  of  stability  at  various  angles  of  inclination 


I 


FORM,  STABILITY,  STRENGTH,  AND  CAPACITY    67 


!♦» 


lO 

o 

«n 

O 

n 

o 

«n 

10 

lO 

CM 

CM 

- 

" 

o 

—  SMOjiooj    SINBWOW   9NriH9IU  — 


I  FORM,  STABILITY.  STRENGTH,  AND  CAPACITY 
Kecently,  the  "  all  wood  "  type  of  collapsible  bulwark  lias 
beoti  accopted  for  open  boate  of  Olaos  Ha,  which  it  in  cousidertxl 
iucreasea  tlii;  stability  and  general  seaworthiness  of  this  particular 
type  of  boat,  and  it  is  anticipated  that  the  same  dettign  of  bulwark 
will  be  brought  forward  by  the  boatbuildcrs  for  the  pontoon 
daas  of  lifeboat. 
The  great  essential  with  tlie  lattcsr  type  of  boat,  is  to  preserve 
a  watertight  permanent  structure  and  possess  a  suiHcient  number 
ol  rehof  valves  to  carry  away  very  quickly  all  surface  water  on 
the  deck. 
The  pontoon  lifeboat  of  Class  Ic,  with  fixed  bulwarks  and 
suitabit)  rehef  valves,  provides  a  strong  and  eiEcient  life-saving 
itppljance,  but  up  till  the  present  date  it  has  not  found  general 
favour  owing  to  the  difficulty  of  stowage. 

Stability  Test. — In   paragraph  (1)  of   General  Uule  5  of   the 
|Lifo-8aving  Appliances  Rules,  it  states  ; — 

"  All  boats  shall  be  properly  constructed  and  shall  be  of  such 
"  form  and  pro|K)i-tions  that  they  ahall  have  ample  stability  iu  a 
"  seaway,  and  sufficient  freeboard  when  loaded  with  their  full 
"  complement  of  persons  and  equipment.  They  shall  be  fitted 
"  and  arranged  to  the  satisfaction  of  the  Board  of  Trade." 

Cases  have  arisen  where  the  dimensions  and  form  of  a  lifeboat 

e  such  as  to  raise  serious  doubts  as  to  their  stabihty.     The  only 

■iray  to  satisfy  one's  judgment  is  Ut  undei'take  a  stability  test  by 

llbading  the  boat  with  weights  equal  to  the  full  number  of  persons 

iried,  and  then  incline  her. 

The    weights  are  arranged  so  that  their  centres   are  12  in. 

ibove  the  thwaitu,  side  benches,  or  lower  Heats,  and  equally 

Edistributcd  throughout  the  length  of  the  boat. 

It,  therefore,  becomes  necessary  to  support  the  weights  by 
mber  above  the  seats,  so  as  to  brmg  their  centres  to  the  12 
^ee,  which  is  asauined  to  be  tlie  height  of  the  centre  of  gravity 
!  a  person  sitting  above  the  thwart  or  scat.  Haif-hundred- 
_  meif^tB  are  usually  employed  for  the  purpose,  as  they  can  be 
eaaily  handled  and  are  to  he  preferred  tw  bags  of  sand.  The  test 
shoidd  be  undertaken  in  still  water  to  faciUt*it«  the  accuracy  of 
the  readings  and  the  residts  From  the  incliuatious. 
^^v  The  boat  is  trimmed  fore  and  aft  on  a  level  keel  and  the 
^^^Beighte  arranged  to  allow  her  to  be  upright  for  the  initial  reading. 
^^H  Two  men  are  usually  left  in  the  boat  to  adjust  the  weights. 
^^H  The  freeboard  is  taken  in  the  upright  condition. 
^^B  Weighbi,  of  known  amount,  are  then  moved  from  one  side 
^^n  the  boat  to  the  other  throu^  a  dednite  distance  d,  as  shown 


70 


SHIPS'  BOATS 


in  Fig.  21,  i.e.  2  to  4  or  1  to  3,  the  weights  being  arranged  in  a 
fore-and-aft  direction,  with  sufficient  space  between,  to  allow  this 
to  be  done. 

As  each  set  of  weights  is  moved  the  alteration  to  the  freeboard 
is  noted  on  both  port  and  starboard  sides. 

Inclinations  are  continued  until  the  gunwale  is  brought  in 
close  proximity  to  the  water-level. 

From  the  information  thus  obtained  a  stability  curve  can  be 
plotted. 

The  following  particulars  are  necessary  before  the  test  takes 
place : — 

(a)  The  actual  weight  of  the  boat. 

(6)  The  total  weight  to  be  placed  on  board  to  represent  the 


Fig.  21. 

full  number  of  persons  and  equipment,  deductions  being  made 
for  the  amount  of  timber  used  for  supporting  the  weights,  and 
for  the  two  men  in  the  boat  adjusting  the  weights. 

(c)  The  density  of  the  water  ;  as  this  affects  the  freeboard. 

(d)  The  boat  must  be  quite  clear  of  internal  water,  unless  a 
comparative  test  is  undertaken  to  ascertain  the  effect  of  internal 
free  water  on  the  stability. 

Inclining  Experiment. — If  we  possess  the  lines  of  a  boat  we 
can  calculate  tlie  position  of  the  centre  of  buoyancy  and  the 
position  of  the  metacentre,  and  the  correct  position  of  the  centre 
of  gravity  and  the  metacentric  height  can  also  be  obtained  by 
moving  known  weights  in  the  actual  boat  through  a  definite 
distance  d  (see  Fig.  21). 


FORM,  STABILITY,  STRENGTH,  AND  CAPACITY    71 

A  plumb-bob  ia  auBpcntled  at  tlm  middle  line  from  a  batten 
secured  in  a  suitable  iioaition. 

A  lower  cross  batten  ia  fixed  between  the  tank  cleading,  at  a 
distftQce  I  below  the  point  of  suspcnsitin  of  the  plumb-bob. 

The  known  weights  are  moved  from  one  aide  t«  the  other 

through  a  distance  d,  and  the  movement  of  the  plumb-bob,  from 

the  upright  position  on  the  lower  cross  batten.'viz,  "  a,"  is  noted. 

The  moved  weif^ht  is  replaced  in  its  original  position,  when 

the  plumb-bob  should  return  to  the  middle  line. 

Weights  of  similar  amount  are  moved  to  the  opposite  aide 
and  the  distance  "  a  "  is  again  noted. 

It  is  evident  that  when  the  boat  is  inclined  ftom  the  upright 

[  position  by  the  movement  of  weights  on  board,  the  centre  of 

I   gravity  will  also  move  out  in  the  same  direction  of  inclination, 

'  and  the  boat  will  come  to  rest  when  the  centre  of  buoyancy  and 

'   the  centre  of  f;ravity  are  in  the  same  vertical  line.     For  small 

angles  of  heel,  the  intersection  of  the  vertical  line  in  the  inclined 

condition  with  the  vertical  line  in  the  upright  condition,  will 

give  the  position  of  the  nietacentre. 

If  the  angle  of  inclination  ia  6. 

tan  6 
P,,.      "Xd 

FtiKrfore  ™  =  w'^9 

If  a  =  the   distance   the   plumb-bob   has   moved  along   the 
lower  batten, 
and  I  =^  length  of  plumb-bob  from  point  of  suspension  to  upper 
edge  of  lower  batten, 

l.ihea  tand=<^ 

Kbo  that  we  arrive  at  an  expreaaion  from  which  the  metacentric 
meigfat  can  be  obtained,  viz,  : — 

VVx? 


J 


I 


72  SHIPS'  BOATS      . 

AHwiTminjr  that  the  wei^t  o{  a  boat  b  116  cwta. :  iveight  iif 
ballast  moved  =  d  cvfta. ;  diataace  through  which  ballatit  is 
moved  =  6'0  ft. ;  length  of  "  f "  =  30  ft. ;  travel  of  plumb-bob 
"(i"=5m.  (■42'); 

.1.  r.M         6  Xli         6x6x3 


The  position  of  the  nietaceutre  above  the  centre  of  buoyancy 
has  already  been  calculated  and  setting  down  2'22  feet  below 
M  we  find  the  position  of  the  centre  of  gravity  of  the  loaded  boat. 

Students  ai-e  referred  ti>  an  interesting  treatment  of  the 
question  of  stability  of  Self-righting  Lifeboats,  by  Mr.  E.  L. 
Attwood,  O.B.E.,  R.CN.C,  in  hia  text-book  on  "  Theoretical 
Naval  Architecture." 

Reference  to  dynamical  stability  is  made  in  Part  Vll., 
Section  B,  in  conjunction  with  '"Siiil  Areaa  and  the  Effect  of 
Wind  Pressure." 

The  subject  of  stability  has  been  treated  at  some  length,  the 
object  of  which  is  to  impress  upon  boatbuildera  and  other  readers 
the  necessity  of  taking  into  consideration  all  the  factors  which 
have  such  an  important  bearing  on  the  general  design  and 
structure  of  a  ship's  boat. 

It  is  therefore  suggested  that,  if  a  little  more  careful  thought 
and  attention  were  given  to  the  practical  application  of  these 
principles,  the  efficiency  of  the  life-saving  equipment  of  our 
merchant  vessels  would  be  considerably  increased. 

STRENGTH. 

The  essential  feature  of  ships'  boats  is  to  save  life  when  it 
becomes  necessary  to  "  abandon  ship." 

The  greatest  stresses  a  boat  will  probably  have  to  meet  with 
will  be  encountered  when  she  is  being  lowered  into  the  water, 
and  not  when  she  ia  actually  waterbome. 

The  scantlings  of  all  boats,  which  form  part  of  the  statutory 
equipment  of  a  vessel,  are  designed  on  the  assumption  that  the 
boats  can  be  lowered  in  safety,  with  the  fuU  load,  from  the  davita 
into  the  water. 

The  details  of  the  scheme  of  scautliijgs  for  wooden  boats  of 
Classes  Ia,  1b,  and  HI,  have,  therefore,  been  drawn  up,  having  in 
view  the  enormous  stresses  to  which  the  boats  may  be  subject«d. 

Combination    of    Frame, — The  first   provision  is  to  secure  a 


FORM,  STABILITY,  STRENGTH,  AND  CAPACITY    73 

Eaiiio  strong  enituj^li  to  aujjport  tlie  heavy  weight  of   peitMJiis 
*rheii  ttie  boat  is  suspetulcd  by  the  falla  from  the  davit  head. 

Special  atteQtioa  must  be  given  to  the  method  of  aeciu-iiig 
Ite  combintttious  of    keel,  hog-piece,  keelson,  stem,  stempOBt, 
Faprons,  and  deadwooda. 

With  the  exception  of  the  hog-pioce,  which  is  fastened  to  the 

keel  with  long  brass  screws,   the  whole  of  the  combinatioDs 

referred  to  must  be  adequately  scarphed  together  and  secured 

Iwith  properly  clenched  bo!t«,  or,  preferably,  nut  and  screw  bolts, 

laviag  their  points  clenched  over  the  heads  of  the  nuts. 

The  deadwo'jds  and  aprons  are  moulded  to  a  size  that  will 

Inw  the  hooded  ends  of  the   planking  being  secured  with  a 

1  double  row  of  fastenings,  and  the  deadwoods  should  be  sided 

Mfo  as  to  provide  a  full  faying  suifacc  for  the  garboard  strake 

Old  the  strake  immediately  above  the  garboard. 

The  ends  of  the  timbers  should  be  notched  into  the  deadwood. 

The  keelson  is  littcd  to  run  tlie  whole  length  of  the  boat, 

I^Karpbing  with  or  lapping  over  the  deadwoods  so  that  the  lilting 

hook  keel  boltfi  grip  the  keelson,  deadwood  and  keel,  whether 

the  boat  is  lifted  in  ordinary  radial  davits  oi  at  the  ends,  as  in  the 

Weltn  standard  type  of  davit. 

The  whole  of  the  combinations  and  tbeit  securities  must  be 
80  ananged  that  each  separate  portion  takes  its  fair  share  of  the 


In  order  that   the  stem  and  aternpost  may  he  eSiciently 

bound  together  at  the  scarph,  the  full  thickness  of  the  keel  is 

inaint£ned  throughout  ita  leugtli,  so  that  the  bearding  of  the 

B«tem  or  sternpost  does  not  comnieace  until  the  upper  edge  of 

■he  keel,  at  least,  is  reached. 

Timbers,— Havmg  provided  a  strong  backbone  for  the  boat, 

)uld  be  given  to  the  timbers  and  planking. 
It  was  quite  a  general  practice  at  one  time,  to  space  the  timbers 
from  8  to  9  in,  apart,  in  the  open  type  of  boats,  and  sometimes 
at  a  greater  distance.     Instructions  now  issued,  make  it  necessary 
~*  0  limit  the  spacing  to  6  in.,  centre  to  centre. 

The  writer  is  fulfly  aware  of  the  heavy  scantlings  of  the  timbers, 
tat  tiie  sizes  are  based  upon  the  great  stresses  to  which  the  boats 
MB  subjected.  Timbers  should  extend  from  gunwale  to  gunwale 
and  attention  should  be  given  to  ascertain  that  no  halt  timbers 
exist,  except  at  the  ends  of  the  boat,  before  the  keelson  is  pliu'ed 

t position. 
Planking. — The   planking  is  worked  to  a  minimum  breadth 
5J  in.  over-all,  except  the  garboard  and  adjacent  strakes. 


at  a 


74 


SinPS'  BOATS 


The  narrowest  strakes  should  be  situated  at  the  bilge.  It  is 
considered  essential  that  the  gaiboard,  bilge,  and  binding  strakes 
should  be  kept  slightly  thicker  than  the  remaining  strakes  of 
planking. 

A  weak  portion  of  the  ordinary  open  type  o£  boat  is  situated 
at  the  bilge,  due  to  the  soleing  away'of  the  plank  edges.  The 
quicker  the  bilge,  the  weaker  becomes  the  section ;  hence  it  ia 
advisable  to  work  an  "easy  bilge"  for  the  planking.  Narrow 
planks  lend  themselves  better  to  the  operation  of  soleing.  In 
any  case  there  is  a  weakness  at  this  particular  part  and  it  becomes 
necessary  to  fit,  fore  and  aft,  in  one  length,  a  bilge  stringer  of 
the  same  scantlings  as  the  rising,  but  througli-fastened  and 
clenched  only  at  alternate  timbers.  If  bilge  planks  were  limited 
m  breadth  to  4J  in.,  it  is  considered  it  would  be  an  advantage  to 
the  boat. 

Stringers. — The  bilge  stringer  in  boats  over  24  ft.  in  length 
ticarph  with  the  lower  breasthook. 

The  rising  is  fitted  to  give  adequate  support  to  the  ends  of 
the  thwarts,  and  if  the  thwarts  are  checked  into  the  rising,  the 
latter  should  be  increased  in  depth  accordingly. 

The  sides  of  the  boat  are  well  held  together  with  a  minimum 
number  of  thwarts,  but  it  ia  considered  generally  by  the  boat- 
builders,  that  all  boats  should  be  fitted  with  double  knees, 
especially  at  the  thwarts  in  way  of  the  gripes. 

Side  benches,  instead  of  scarphing  with  the  thwarts,  are 
continued  in  as  long  lengths  as  possible  above  the  thwarts  and 
well  secured  by  heavy  screws  to  the  thwarts,  or  preferably"  bolts, 
where  single  knees  only  are  fitted. 

The  upper  etrake,  rubber  and  gimwale,  provide  a  very 
efficient  girder  to  resist  the  sudden  stresses  which  oome 
upon  the  boat  when  being  lowered  from  a  great  height,  provided 
an  efficieJit  connection  is  made  between  the ,  timbers  and  the 
gunwale. 

Gunwale. — Boatbuilders  are  unanimous  in  their  opinion  that 
the  most  efficient  ^zunwale  is  the  "  box  "  type. 

It  is  the  writer's  confirmed  opinion  that  when  boats  are 
lowered  from  davits  situated  a  great  distance  above  the  water, 
where  there  ia  every  chance  for  the  boat  to  swing  and  come  in 
violent  contact  with  the  ship's  aide,  the  ordinary  solid  gunwale, 
in  these  circumstances,  is  a  source  of  danger,  arising  from  its 
inadequate  coimoction  with  the  timbers.  There  is  plenty  of 
evidence  from  practical  experience  to  support  this  opinion. 

The  box  gunwale  is  infinitely  stronger,  more  resilient  to  sudden 


FORM,  STABILITY,  STRENGTH,   AND  CAPACITY    75 

blows  and  distributes  the  stresses  received  through  the  timbers 
to  which  it  is  connected. 

Lifting-Hooks. — The  position  of  the  lifting-hooks  has  a  material 
effect  on  the  question  of  the  stresses  'coming  on  the  boat. 
The  ideal  position  would  be  at  the  quarter-length  of  boat,  where 
the  supporting  chocks  are  now  fitted,  but  this  does  not  suit  the 
radial  type  of  davit,  and  the  hooks  would  interfere  with  the 
seating  accommodation.  The  nearer  the  lifting-hooks  are  fitted 
to  the  ends  of  the  boat  the  greater  will  be  the  stress  on  the  boat 
when  hanging  from  the  davits.  It  is,  therefore,  necessary  in 
the  case  of  those  particular  davits  where  the  lifting-hooks  are 
fitted  from  15  to  18  in.  from  the  front  of  the  stem  or  back 
of  stempost,  to  provide  special  strengthening  at  the  ends. 

These  various  points  are  referred  to  in  greater  detail  in  the 
general  description  of  the  construction  of  the  different  types  of 
boats. 

To  provide  for  the  "  unusual  circumstance  "  when  passengers 
may  probably  be  in  a  condition  of  panic,  and  the  crew  have 
considerable  difficulty  to  control  the  lowering  of  the  boats,  it  is 
essential  to  maintain  a  high  factor  of  safety  in  the  strength 
of  the  boats  and  in  all  the  details  connected  with  the  launching 
appliances. 

Ships'  officers  have  already  confirmed  the  opinion  of  the 
writer,  that  the  type  of  lifeboat  now  placed  on  merchant  vessels 
is  a  great  improvement  on  the  old  standard  of  construction,  and 
that  expression  of  opinion  is  base^  on  the  results  of  actual  ex- 
perience, when  vessels  under  their  command  have  been  torpedoed. 

Supposing  it  became  necessary  to  ascertain  the  amount  of 
stress  exerted  on  the  gunwale  of  an  open  boat  of  Class  Ia  (clinker 
built)  when  suspended  from  ordinary  radial  davits  and  having 
the  full  number  of  persons  on  board,  the  calculation  involved 
is  arranged  in  the  following  order  : — 

As  an  example  take  a  Ufeboat  with  dimensions  : — 

280'  X  8-5'  X  3-5' 


The  scantlings  of  the  material  running  fore  and  aft  are  : — 

Keel     .     .     .   5^''  X  3''   Rock  ebn. 

Hog-piece  .      .   SJ''  x  1"       .,       „ 

Keelson     .      .   6^  X  3}"     „ 

(scored  over 
timbers). 

Bilge  8triii(^^cr     V    X  J"  Pitch  pine. 

Rising  .      .      .   V   XV 

Side  benches     IV   X  IJ"'     „ 

76  SHIPS'  BOATS 

Rubber      .       1^"  X  li"  Rock  elm. 
Planking    .      .      .      .    f'  Larch. 
Upper  strake     Dj''  X   f  Teak. 
Solid  gunwale    2|''  X  2^"  Rock  elm. 
Box  gunwale     I''     X  3J''     „       „ 
Depth  of  thwart  below  gunwale  =  11  in. 


Estitnated  WeigJUs. 

Cwt8. 

Boat,  including  buoyancy  air-ca«es  =    35*7 

Equipment ==6*5 

Persons  (50  in  number)       .      .      .  =    73*7 

Total  load    ....       1159 

A^uming  the  lifting-hooks  to  be  situated  3  ft.  from  the 
stem  and  sternpost  rabbeta,  then  the  distance  between  the  hooks 
will  be  22  ft. 

The  bending  moment  of  a  beam  evenly  loaded  and  supported 

at  the  ends,  is  —tt-. 

o 

The  bending  moment  of  a  beam  with  load  at  middle  of  length 

and  supported  at  ends,  is  -j- . 

Therefore   assume  bending  moment   of   loaded  boat  under 

conditions  of  support  as    ^.    # 

u 

W  =  tot^l  weight  of  boat  and  persons. 
L  =  distance  between  lifting  hooks. 

Therefore         BM  =  ^ ^""''[^  ^^"^  =  425  f r.-cwts. 

To  calculate  the  compression  on  the  gunwale  we  use  the 
followiui'  formula  : — 


'r> 


My 

/;  represents  the  intensity  of  the  stress  exerted  on  the  gunwale 
due  to  bending,  at  any  point  of  the  section,  at  a  distance  ?/  from 
the  Neutral  Axis. 

M  is  the  Bending  Moment,  and 

I  is  the  Moment  of  Inertia  of  the  section  about  its  Neutral 


FORM,  STABILITY,  STRENGTH,  AND  CAPACITY    77 


The  first  operation  is  to  find  the  Neutral  Axis  and  moment  of 
inertia  of  the  midship  section. 

SnUkHE 


B/LGC  SrPftNG€R 

^jnjureLawt 

^^-^MiNG 

Fio.  22. 


Assume  Neutral  Axis  as  2  ft.  3  in.  below  gunwale,  and  life- 
boat fitted  with  solid  gunwale. 


Rbfsrenoe  is  made  to  Fio.  22. 


Item. 


Section. 


Area 
in  sq. 
inohee. 

A. 


Distance  in 

feet  from 

assumed 

N.A. 


Moment 


At/ 


MofI 

abont 

aasomed 

ir.A. 

Air- 


( 


M  of  I  of  seotion  about 

AJb* 

its  own  axis  « 15- 


Qunwale 
Top  stiake    . 
Si&  planking 
Side  seats 
Rubber   . 
Rising 


lUma  obovt  assumed  Neutral  Axis, 


2J''x2}' 
bV  X  r 

2irxr+A 


th 


\Yx\v 


6-63 
3-94 
14*96 
16-75 
2-26 
4-00 


215 
2*04 
0-90 
1-37 
1-76 
105 


12*08 
I  8-04 
,  13-46 
I  21-58 
;  3-94 
4-20 


I. 


25-97  I 
16-40 
12-11 
29*56 

6-90 

4*41 


Ax  14*95  Xl-8««4-a4 


Total  M  above  axis  63*30  j 
Items  below  assumed  Neutral  Axis. 


Bilge  planking  .    18*xr+A*'  12-37, 

Bottom  planking  33*'xr+ A***    22-69 

Kaelbalf      .     .'     6J'xir 

Hog  half  rx2r 

Keelson  half  4^x1^ 

Bilgp  stringer     .         4'  X  J'         

« 

Total  sectional  an>a  103*20 


8-26 
2*63 

7-74 
3-00 


0-5 
1*0 
1-5 
1-2 
0-9 
0*5 

Total  M 
below  axis 


I 


6*19 
22-69 
12-38 
3*16 
6-97 
1*50 


8*10  i^X  12*37  X*8*«>*66 
22*69 
18*57 

3-79 

6-27 

0-75 


1 52*89     150*52 


Moment  above  axis  63*30 
Difference  10-41 


=  -10 


Distance  of    Neutral  Axis(       lOjU^   .^ 
above  Assumed  Axis        j""  103-20 

Assumed  N. A. below  gunwale =2-25 


Actual  N.A.  below  gunwale    =2-16 

NoTB. — i^n*''  added  to^planking  to  allow  for  landings. 


-f4-70 

Ay  s- 150-52 

Moment  of  Inertial  ___,--.  „ 
about  Assumed  Axis  f      oo  -  ss 
(Correction  for  C.G.)  10320  x  -1*=     1-03 

M  of  I  about  actual  \    ,,^  .1 
Neutral  Axis  |=154  l» 

For  both  sides     2 

308-38 


78  SHIPS'  BOATS 

I  =  moment  of  inertia  of  section  '  =  308*38. 

y  =>  distance  of  neutral  axis  below  gunwale  =    2*15  ft. 
M  =j  bending  moment  =>  425  ft.-cwts. 

p  =  stress  on  gunwale,  in  cwts.  per  sq.  inch.  • 

My 

_  425  X  2-15 

"~     308-38 

=>  2*96  cwts.  per  sq.  in. 

Sectional  area  of  gunwale     .     .     .   =  5*63  sq.  in. 
Total  compressive  stress  on  gunwale  =  5-63  X  2*96 

=  16-68  cwts. 

If  we  consider  the  gunwale  as  a  pillar  held  firmly  at  the 
thwarts  spaced  4  ft.  2  in.  apart,  the  strength  of  the  gimwale  is 
obtained  by  Euler's  formula  as  follows  : — 

2  EI 


a) 


p  =  greatest  load  consistent  with  safety. 

E  =>  modulus  of  elasticity  =  700  tons  per  sq.  in. 

I  =  moment  of  inertia  =.  ^  -— -^=i  2*93 

12 

I  =  length  in  inches. 

Q  1^2  v/ 700x2-93 
7)  =  3142  x-^  — ^^ 
^  25  X  25 

=  32-34  tons. 

CAPACITY. 

There  appears  to  be  doubt  in  the  minds  of  shipbuilders  and 
others  as  to  where  the  dimensions  of  an  open  boat  of  Class  I.  are 
measured.  The  extreme  length  of  the  boat  is  taken  from  the 
fore  side  of  the  stem-head,  to  the  after  side  of  the  stempost-head, 
or  in  other  words  it  is  the  "  over-all  "  length. 

The  external  'capacity  length  is  taken  from  the  intersection  of 
the  outside  of  the  planking  with  the  stem,  to  the  corresponding 
point  at  the  stempost,  ot,  in  the  case  of  a  square-stemed  boat, 
to  the  after  side  of  the  transom.  This  is  the  length  used  in 
conjimction  with  the  formula  for  obtaining  the  capacity  of  a 
boat  (LxBxDxO-6)  and  is  the  recognised  length.  When  we 
refer  to  a  boat  as  being  28  feet  in  length,  it  is  the  external  capacity 
U         fiiftt  18  meant  and  not  the  extreme  length. 


I 


FORM,   STABILITY,  STRENGTH,   AND   CAPACITY     79 

Shipbuilders  should  bo  careful,  therelore,  in  sending  lo  the 
boatbuildera  the  position  of  the  lifting-hooks,  tii  distinctly  state 
where  they  are  to  be  fitt«d  in  relation  to  the  outside  of  plank 
rabbet,  or  to  the  stem  and  stempost-heads.  In  addition,  the 
distance  between  the  hooks  should  be  j^iven.  Inconvenience 
will  often  be  avoided  if  attention  is  directed  to  this  point. 

The  internal  capacity  length  ia  taken  from  the  inside  of  the 
planking  or  platinf;  at  the  stem  to  the  corresponding  point  at 
the  stempost,  and  in  the  case  of  a  sqiiare-stemed  boat,  the 
length  is  measuretl  to  the  inside  of  the  transom.  This  length  is 
only  used  when  Stirling's  Rule  is  being  employed  for  asccrt«ining 
correctly  the  internal  cubic  capacity  of  a  boat. 

The  breadth  of  a  boat  is  taken  from  the  outside  of  the  planking 
at  the  point  where  the  breadth  of  the  boat  in  the  greatest.  This 
dimension  is  usually  measured  from  the  outaideof  the  upper  strakes. 
The  breadths  used  with  Stirling's  Rule  arc  taken  from  the 
inside  of  the  planking.  Shipbuilders  should  keep  in  mind  when 
arrangibg  the  outreach  of  davits,  to  take  into  account  the 
thickness  of  the  rubbers,  or  rope  fenders  if  such  are  fitted,  These 
items  project  beyond  the  maximum  recognised  breadth. 

The  recognised  deplh  is  the  distance  measured  amidships, 
between  the  inside  surface  of  the  planking  at  the  keel,  to  the  level 
of  the  top  of  gimwale. 

The  number  of  persons  that  can  be  allotted  to  an  open  boat 
of  Class  I.  depends,  in  the  first  place,  on  the  cubic  capacity,  and 
secondly,  whether  proper  seating  arrangements  can  be  made  for 
tiie  number  ascertained  by  dividing  the  cubic  capacity  by  the 
correct  unit  of  capacity,  provided,  of  course,  that  the  dimensione 
and  form  are  suitable. 

The  cubic  capacity  of  motor  boats,  and  deck  areas  of  pontoon 
boats  and  of  open  boataof  Class  1 1,  are  separately  dealt  with  under 
i^ar  own  particular  section. 

The  various  dimensions  before  mentioned  are  illustrated  in 
lllg.  23. 

I  The  total  volume  of  the  buoyancy  air-casea  ia  to  be  not  less 
Itiian  one-tenth  of  the  cubic  capaciti/  of  all  open  boats  of  Class  Ia. 
~  Atbuilders  need  to  keep  this  provision  in  mind.  The  volume 
f€i  air-cases  is  not  calculated  upon  the  number  of  person.'}  carried, 
kand  it  is  usual  for  tinsmiths  to  add  a  percentage  to  the  cubic 
t  given  for  the  number  of  persons  carried,  calculated  by  the 
lL>jBxDx06  Rule.  As  an  example,  a  Class  Ia  open  boat, 
■wi^  dimensions  280'x8'5'x35'  giving  50  persons  by  the  rule 
Vsientioned,  would  probably  have  a  cubic  capacity  between  540 


SHIPS'  BOATS 


EXTREME   LENOTM     - 


FORM,  STABILITY,  STRENGTH,  AND  CAPACITY    SI 

auii  560  ft.,  if  measured  by  Stirliiifj'a  Rule,  and  in  that  caau  the 
buoyancy  air-cascu  wuuld  have  to  be  54  or  56  cub.  ft.  and  not 
50  cub.  ft. 

Full  detaibi  are  given  in  the  Rules  for  Life-siiviny  Appliances, 
am  to  the  correct  method  of  obtaining  the  cubic  capacity  of  open 
boats  of  Class  I.,  which  are  an  follows  :— 

"  The  cubic  capacity  shall  be  determined  by  the  following 
■'  formula  :— 

■'  Capacity  =     (4A  +  2B  +  ■IC) 

"  I  denotes  the  length  of  the  boat  in  feet,  fi'om  the  iutiidc  of 
"  the  pbnking  or  plating  at  the  stem,  to  the  corresponding  point 
'•  at  the  uternpost ;  in  the  cajse  of  a  boat  with  a  square  stem  the 
"  length  is  measured  to  the  inside  of  the  transom. 

"  A,  B,  C  denote  respectively  the  areas  of  the  cross-sections  at 
'  the  quarter  length  forward,  amidships,  and  the  quarter  length 
'  aft,  which  correspond  to  the  three  point*  obtained  by  dividing 
"  I  into  four  equal  parts  (tlie  areas  corresponding  to  the  two  ends 
"  of  the  boat  are  considered  negUgible). 

■■  The  areas  A,  B,  C  ahalt  be  deemed  to  be  given  in  square  feet 
"  by  the  successive  application  of  the  following  formula  to  each  of 
"  the  three  croas-aectiona  : — 

f, 
"  Area  = 


"  h  denotes  the  dejAk  measured  in  feet  inside  the  planking 
"or  plating  from  the  kee!  to  the  level  of  the  gunwale,  or,  in 
"  certain  cases,  to  a  lower  level  as  determined  hereafter. 

"  a,  b,  c,  d,  e,  denote  the  horizontal  breadths  of  the  boat, 
'*  measured  in  feet,  to  the  inside  of  the  planking  at  the  upper  and 
"  lower  points  of  the  depth  and  at  the  throe  points  obtained  by 
"  dividing  A  mto  four  equal  parta  (n  and  e  being  the  breadths  at 
"  the  extreme  pointa  and  c  at  the  middle  point,  of  h). 

"  If  the  sheer  of  the  gunwale,  measured  at  the  two  points 
'■  situated  ut  a  quarter  of  the  length  of  the  boat  from  the  ends, 
"  exceeds  1  per  cent,  of  the  length  of  the  boat,  the  depth 
"  employed  in  calculating  the  area  of  the  cross-sections  A  or  0 
"shall  be  deemed  to  be  the  depth  amidships  plus  1  per  cent,  of 
"  the  length  of  the  boat." 

There  are  certain  limitations  to  the  depth  used  for  calcu- 
lating the  capacity  of  an  open  boat  of  Class  1a,  but  these  would 
be  unnecessary  if  the  dimensions  of  boats  indicated  in  Table  VII. 


82 


SHIPS'  BOATS 


wave  worked  U*,  ua  anything  approaciiiuf'  io  per  cent,  nf  the 
breadth  for  the  depth,  is  considered  by  practical  boatbiiilders 
to  be  unsuitable  for  a  rowing  boat.  The  limitatiooB  referred 
to  are  as  followa  : — 

(a)  "  If  the  depth  of  the  boat  amidshipM  exceeds  45  per  cent. 
•'  of  the  breadth,  the  depth  employed  in  calciUatiag  the  area  of 
■■  the  midKhip  cross-section  B,  shall  be  deemed  to  be  equal  to  45  per 
"  cent,  of  the  breadth,  and  the  depth  employed  in  calculating  the 
"  areas  of  the  quarter  length  sections  A  and  C,  shall  be  obtained  by 
"  increasing  this  last  figure  by  an  amount  equal  to  1  per  cent,  of 
■■  the  length  of  the  boat,  provided  that  in  no  case  shall  the  depths 
"  employed  in  the  calculation  exceed  the  actual  depths  at  these 
"  points. 

(b)  "  If  the  depth  of  the  boat  is  greater  than  4  feet,  the  number 
"  of  pereona  given  by  the  apphcation  of  these  General  Rules,  shall 
■'  be  reduced  in  proportion  to  the  ratio  of  4  feet  to  the  actual 
■'  depth,  until  the  boat  has  been  tested  afloat  with  that  number 
"  of  persons  on  board,  all  wearing  life  jackets,  and  the  test  has 
"  proved  aatiafactory," 

The  details  in  calculating  the  internal  cubic  capacity  of  an 
open  boat  of  Olaaa  Ja  with  dimensions  28-0'x8-i3'x3'5'  are 
shown  on  p.  83,  and  it  will  be  seen  that  if  twenty  boats  in  one 
boat-yard  are  to  be  measured  by  Stirling's  Rule  and  calculations 
made  from  the  results,  the  operation  is  one  which  entaila  a 
great  deal  of  labour.  Life  ia  too  short  for  this  rule  to  be  con- 
stantly in  operation.  If  a  coofiicient  of  form  ia  recognised  and 
check  dimensions  be  applied  tt>  the  forward  and  after  quarter 
cross-sections  to  enable  the  boatbuilders  to  make  suitable  moulds, 
there  would  be  very  few  occasions  when  it  would  become  neces- 
sary to  use  the  exact  method  of  obtaining  the  capacity.  The 
following  rule  would,  therefore,  become  operative,  viz : — 

(c)  "  The  cubic  capacity  of  a  boat  may  be  assumed  to  be  the 
"  product  of  the  length,  the  breadth,  and  the  depth,  umltiplied  by 
■'  06  in  cases  where  it  is  clear  that  this  formula  does  not  give  a 
"greater  capacity  than  that  obtained  by  the  above  method  (at 
"  (o)  and  {b}).  The  dimeusioua  shall  then  be  measured  in  the 
"  following  manner  : — 

"  Length  :  From  the  intersection  of  the  outside  of  the  phinking 
"  with  the  stem  to  the  corresponding  point  at  the  stempoat,  or, 
"in  the  case  of  a  square-steraed  boat,  to  the  after  side  of  the 
"  transom. 

"  Breadth :  From  the  outside  of  the  planking  at  the  point 
"  whei-e  the  breadth  of  the  boat  is  greatest. 


fORM,   STABILITY,  STRENGTH,   AND  CAPACaTY  83 

"  Depth :  Amidships,  inside  the  planking  from  the  keel  to 
"  the  level  of  the  gunwale,  but  the  depth  used  in  calculating  the 
"  cubic  capacity  may  not  in  any  case  exceed  45  per  cent,  of  the 
"  breadth, 

"  In  all  cases  the  shipowner  shall  have  the  right  to  require 
"  that  the  cubic  capacity  of  the  boat  shall  be  determined  by 
"  the  exact  measurement." 

When  referring  to  the  specimen  calculation  of  the  capacity 
of  an  open  boat  by  Stirling's  Rule,  attention  should  be  directed 
to  the  section  of  Fig.  23. 

Cil^JULATIUN    IfOR   InTKHNAL  CAPACITlf    OF   AN    OfBM    BoAI   Q¥  ClASS  1. 

Uiuipuaions :  28-0'  x  8*5'  x  3-5'. 


:i3-32 

ltl'58 
3012 


7-70 
7-40 

7-05 


Intenial  i»[>iicitv  !i-iiBt]i— ^71 


Cu<llit:icttt  uf  /orm^         ^"liSU 
K  limber  of  ih'ihodh  by  cii[jBcity  =5fi 
JiumU'r  uf  pcrsoua  limited  byt  _^„, 

a'aliiig  arningomtnts  /  ^ 


DIH3J3ti 
Total  intcmnl  CB]iftcity  =  Sfll  cub.  (t. 


SECTION  A.~TiMBEH  :  CONVERSION,  SEASONING, 
DISEASES,  SELECTION,  STKENUTH,  ETC. 

TuE  first  British  writer  to  f^ive  th«  benefit  (if  his  invcHtigationB 
by  publishing  a  treatise  on  the  subject  of  "  Timber '"  was  in  tha 
year  1664 ;  and  since  that  date  a  great  wcaltli  of  information 
has  been  collected,  as  a  result  of  experimental  and  research  work, 
by  many  eminent  and  distinguished  experts. 

In  the  days  of  wooden  shipbuilding,  the  subject  of  timber 
was  one  that  attracted  the  attention  of  some  of  the  best  scientists 
of  that  period,  particularly  with  reference  tti  its  treatment  in 
order  to  prevent  decay,  and  to  increase  the  lasting  qualities  ol 
a  vessel. 

Of  recent  years  valuable  help  has  been  given  to  shipbuilders 
and  other  traders  associated  with  the  use  of  wood,  by  the 
publication  of  text^hooks  containing  the  results  of  the  practical 
experience  of  such  authors  as  Professor  Marshall  Ward,  D.Sc., 
Mr.  T.  D.  Laslett,  Mr.  J.  R.  Baterden,  and,  more  recently,  Mr. 
Webster  who  has  devoted  his  attention  to  British  home-grown 
timber. 

If  students  wish  to  advance  their  knowlec^e  oi  the  subject, 
they  arc  recommended  to  read  the  published  works  of  these 
authors. 

It  is  not  the  intention  of  the  writer,  in  the  present  section, 
to  enter  into  any  great  detail  on  the  physiolo^  of  trees,  but 
only  to  collect  a  few  sahent  features  of  the  subject,  combined 
with  the  result  of  some  practical  experience,  which  may  help  in 
the  investigation  of  the  best  methods  to  be  used  in  selecting,  pre- 
serving, and  working  timber  into  the  construction  of  ships'  boats. 

As  an  Empire  and  a  Nation  the  "  Great  War  "  has  taught  us 
many  things,  and  the  urgency  of  forestry  development,  as  one  of 
the  problems  in  the  national  reconstruction  scheme,  is  of  the 
greatest  importance. 

In  proportion  to  its  size  Great  Britain  has  less  woodland  than 


J 


TIMBER:   CONVERSION,    ETC. 

any  otiier  country  in  Europe  with  the  exception  of  Portugal, 
and  inipoT*6  more  timber  than  any  other  country  in  the  world. 

To  increase  our  own  national  r€aourcefi  and  make  this  countrj 
independent  of  auch  a  volimie  of  imported  timber,  it  isconsidBred  bv 
experts  that  it  wiU  be  neceasary  to  afforest  at  least  1,500,000  acrea. 

During  the  European  War  we  felt  the  difficulty  very  acutely  in 
not  having  sufficient  seasoned  material  to  meet  one-twentieth  of 
the  demand.  Substitutes  have  been  found  to  meet  the  urgency, 
but  the  subject  is  one  of  the  greatest  importance  for  future 
consideration. 

Growth  of  Timber. — If  we  examine  the  cross-section  of  a 
balk  of  timber  we  see  that  it  is  made  up  of  three  distinct  portions, 


viz.  the  pith  at  the  centre  of  the  tree,  the  heartwood.  and  the  sap. 
The  tree  appears  to  be  bound  together  in  its  structure  by  a 
number  of  layers  nr  anmial  rings,  which  vary  in  thiekneaa.  bein^ 
[  narrower  at  the  centre  and  becoming  wider  towards  the  outer 
I  surface.  Each  of  these  layers  are  made  up  of  two  distinct  parte 
I  (see  Fig.  24),  the  lighter  and  larger  being  the  spring-grown  wood 
T  and  the  darker  being  the  autumn  wood,  the  latter  being  much 
(  harder  than  the  former. 

We  are  thus  able  to  approximate  to  the  age  of  the  tree  by  the 

I  number  of  annual  rings.     A  layer  may  vary  in  thickness  owing 

I'to  one  portion  of  the  tree  having  a  better  situation  than  the 

fother.    Trees  grown  in  high  altitudes  do  not  show  such  a  distinct 

wntrast  between  the  spring  and  autumn  wood,  but  where  there 

B  rapid  changes  in  the  seasons,  the  contrast  is  magnified.     In 

Ktropical  countries  the  rings  appear  to  nm  into  one  another. 


I 


80 


SinPS'  BOATS 


The  thicknesfl  of  the  annual  ringa  partly  governs  the  c 
of  timber  into  two  distinct  claasea,  viz.  hard  and  soft  woods. 
All  timber  converted  from  trees  which  are  cone  bearing  and 
have  Hpikea  instead  of  leaves,  is  of  the  soft  wood  class,  being 
wider  rinj^ed  and  quicker  in  growth.  The  slower  growing  trees 
which  bear  leaves,  produce  hard  wood.  Some  of  the  so-called 
hard  woods  are  found  to  be  softer  than  the  generally  accepted 
"  soft  woods  "  and  it  is,  therefore,  eBsential  in  formulating 
specifications  to  distinctly  name  the  particular  specicB  of  timber, 
instead  of  using  the  general  terra  "  haid  wood." 

The  lighter  coloured  portion  of  the  timber  is  the  sap  and  of 
least  value  for  convei'sion,  containing  a  greater  quantity  of 
moisture  than  the  heart  wood,  and  tlierefore  more  liable  to  the 
attacks  of  disease. 

The  sap  is  the  passage  through  which  the  tree  derives  its 
nutriment  or  sustenance,  and  if  this  is  removed  the  tree  will 
eventually  die.  In  process  of  time  the  sap  wood  becomes  heart 
wood. 

If  we  were  able  to  examine  verj-  closely  and  minutely  the 
structure  of  the  section  of  a  tree  we  should  find  that  it  appears 
to  be  made  up  of  a  number  of  long  and  narrow  cells  full  of 
moisture,  the  shell  varying  in  thicknesfl  according  to  the  hardness 
of  the  wood.  The  nearer  to  the  pith  or  heart  wood  we  examine, 
the  less  moisture  we  find,  and  the  closer  together  become  the 
cells. 

The  nutriment  is  conveyed  from  the  roots  upwards  through 
the  passage  cells  of  the  sap  wood  to  the  leaves,  and  in  their  turn 
the  leaves  give  off  oxygen  and  take  into  themselves  gaseous  nutri- 
ment from  the  atmosphere.  Thi-*  passes  through  some  peculiar 
process  of  solidification  and  returns  through  the  bark,  which 
causes  it  to  expand  and  allows  the  more  perfected  sap  to  fill  the 
cavity  and  become  hardened.  This  operation  thus  produces  a 
distinct  layer  <jf  wood  as  indicating  adefinite  period  of  growth. 

Rimniug  from  the  centre  or  pith  in  a  radial  direction  at  right 
angles  to  the  longitudinal  cells,  arc  very  hard  and  thin  cells 
called  medullary  rays  (see  Fig.  24),  which  serve  to  connect  the 
various  annual  rings  and  keep  open  a  passage  for  tlie  conveyance 
of  life  to  the  centre  portiim  of  the  tree  and  which  alao  relievos  to 
some  extent  the  constant  pressure  from  the  contraction  of  the 
ringa  or  layers.  Tlie  medullary  rays  of  uak  are  very  noticeable 
and  pnidnce  a  fine  silky  appearance  when  the  timber  is  cut  on  the 
"  Quarter  Sawing  "  methinl. 

a.— Trees  should   be  felled  when  they  arrive  at  a 


I 


TIMBER:  CONVERSION.    ETC. 


87 


^^t  mature  age,  that  is  to  say,  when  the  largest  poition  of  tlie  tree  is 
^^K  lieart  wood  and  the  sap  has  become  solidiiied  and  elastic,  the  tree 
^^Tis  then  in  tts  strongest  and  moat  suitable  condition  lor  conversion. 
^B  If  the  tree  is  allowed  to  stand  beyond  this  condition  of  maturity 
^F  the  hsart  wood  becomes  brittle  and  loses  it6  elasticity  and  strength, 
and  being  in  a  condition  of  "  decline  "  it  becomes  exposed  to  the 
effects  of  decay. 

On  the  other  hand,  if  the  tree  is  feJled  before  this  condition  of 
maturity,  we  find  that  it  contains  a  large  portion  of  sap  wood  and 
consequently  is  full  of  moisture.  It  is,  therefore,  not  so  durable, 
strong,  or  tough,  and  the  timber  becomes  more  susceptible  to  dry 

Iiot  and  other  diseases. 
The  condition  of  maturity  also  depends  upon  wliether  the 
tree  is  of  hard  or  soft  wood.     The  rapid-lowing  trees,  whose 
annual  rings  are  wider  apart,  are  felled  before  those  of  a  slower 
growing  nature  with  armual  rings  much  closer  together. 
There  are  two  periods  in  the  year  when  the  trees  are  in  a 
condition  of  vegetation,  viz.  the  spring  and  the  autumn,  more 
eepecially  during  the  former  season  when  the  bulk  of  the  new 
wood  is  formed,  and  it  is,  therefore,  very  essential  that  the  tree 
should  be  felled  during  the  period  of  rest  in  midflummer  or  winter, 
preferably  during  the  latter  season  after  the  autumn  growth  has 
taken  place  and  which  is  of  more  value  than  the  spring  sap  wood. 
It  used  to  be  quite  a  common  practice  to  strip  the  bark  oJT 
^H     tJie  trees  in  the  spring  and  allow  them  to  stand  in  this  condition 
^K   for  twelve  months,  the  reason  given  for  such  procedure  being  that 
^B   the  sap  was  hardened  and  t)ie  strength  of  the  tree  increased. 
^H        The  bark  of  the  oak  tree  is  of  great  commercial  value  and  is 
^H'UBually  stripped  in  the  spring,  being  more  easily  detached  at  that 
^^Kperiod  of  the  year. 

^^B  During  the  present  European  war  the  demand  for  home- 
^^ftjgrown  timber  was  greater  than  the  supply,  with  the  residt  that 
^^Ktimber  was  felled  at  all  seasons  of  the  year,  greatly  to  the 
^^R  detriment  of  the  lasting  quahties  of  the  wood. 

There  are  certain  recognised  terms  applied  to  timber  in  its 
various  stages  of  conversion. 

TiitAer  is  the  name  applied  to  the  tnmk  or  body  of  the  tree 
aft«r  it  has  reached  a  diameter  of  eight  inches.  The  loff  is  the 
trunk  of  the  tree  with  its  hark  and  branches  removed ;  and  when 
this  is  trimmed  and  sawn  into  square  sections  it  is  then  termed  a 

Ibaik  and  from  the  balk  are  produced  planhs  and  deals,  the  former 
bnng  from  two  to  six  inches  in  thickness  and  from  eleven  inches 
Id  widt^,  the  latter  varying  in  thickness  from  two  to  four  inches 


88 


SHIPS'  BOATS 


and  nine  incliea  wide.  Boards  are  thin  pieces  of  timber  of  any 
width. 

Loga  are  usually  seasoned  in  the  open  and  then  cut  into 
planks.  Two  methods  are  adopted,  the  usual  practice  in  the 
boat  yard  is  the  easier  one  and  is  termed  "  hastard  samng " 
{Fig.  25),  i.e.  cutting  the  log  longitudinally  into  planks,  and 
although  this  is  considered  the  more  economical  for  conversion 
the  quahty  of  the  planlra  will  vary  considerably,  those  which  are 
cut  at  the  centre  of  the  log  at  right  angles  to  the  medullary  rays 
will  have  very  little  sap,  but  the  planks  cut  near  the  outer  edges 
will  contain  a  large  proportion  of  sap. 

Quarter  samw)  (Fig.  26)  divides  the  log  into  four  parts  and 
cuts  the  planka  from  each  individual  part  at  right  anglea  to  the 
annual  rings.     This  process  enables  one  to  obtain  the  minimum 


amount  of  sap,  and  as  the  medullary  rays  radiate  from  the  centre 
of  the  log  and  at  right  angles  to  the  rings,  the  full  advantage  of 
the  silky  grain  of  oak  is  obtained.  This  method  is  often  adopted 
for  cabinet  maker's  work,  but  is  not  often  reported  to  in  cutting 
material  for  boatbuilding. 

Seasoning. — The  purpose  of  seasoning  timber  b  to  extract 
the  moisture  from  the  cells.  As  already  explained  the  shell  of 
the  cells  of  all  hard  wood  is  thicket  than  those  of  the  soft  wood 
and  more  easily  split  if  dried  with  rapidity,  not  being  able  to 
adjust  itself  to  the  new  conditions.  Timber  of  the  character 
of  oak  and  elm,  therefore,  needs  slower  seasoning  to  prevent 
splitting. 

During  the  process  of  seasoning,  timber  loses  weight  con- 
siderably but  increases  in  strength.  Stresses  are  constantly  in 
operation  tending  to  distort  and  injure  the  fibre  by  contracting 
the   longitudinal   cells   and   medullary   rays,     A\Tiece   balks   or 


TIMBER:  CONVERSION,   ETC.  89 

planka  of  hard  wood  are  exposed  at  the  ends  they  naturally  dry 
quicker  at  these  positions  and  the  distortion  is  more  noticeable. 

The  loss  of  weight  due  to  seaaoniug,  in  some  of  the  moat 
important  woods  used  in  brtatbnilding,  is  as  follows  : — 

Red  pine 12-25  per  cent. 

Yellow  pine 18-27 

Larch 18-27 

British  oak 16-30 

Elm 40 

Mahogany 16-2ri 

One  of  the  moat  important  features  in  connection  with  the 
construction  of  ships'  boats  is  the  question  of  the  satisfactory 
se^aaoning  of  timber. 

During  the  war  the  boatbuilders  were  handicapped  through 
the  necessity  of  using  the  only  available  supply  of  timber,  whieh 
was  home-grown  and  nished  on  the  market  to  meet  the  heavy 
demand,  but  the  material  was  quite  out  of  condition  to  suit 
the  requiremente, 

During  normal  times  the  majority  of  the  builders  are  inclined 
to  work  on  the  "  hand  to  mouth  "  principle,  without  anticipating 
events  and  keeping  a  good  stock  of  timber  in  store,  well  pinned 
down  for  seasoning.  It  is  a  policy  that  does  not  eventually  pay. 
The  most  successful  builder  is  the  man  who  makes  his  plans  for 
the  stocking  of  the  timber  yard  twelve  months  ahead  of  his 
requirements,  to  enable  him  to  have  at  his  disposal  material 
which  has  been  well  seasoned. 

Ab  soon  as  the  planks  are  cut  from  the  log  or  balk,  they  should 
be  -placfd  under  cover,  on  a  dry  foundation,  protected  from  damp- 
ness and  wind,  but  allowed  a  free  circulation  or  current  of  air. 
To  obtain  the  maximum  amount  of  durability,  toughness,  and 
elasticity,  it  is  eaaontial  that  the  timber  should  be  seasoned 
slowly. 

Hot  air  apphed  under  preaaure  is  sometimes  resorted  to  in 
order  to  shorten  the  period  of  seasoning,  and  although  some 
experts  maintain  that  steamed  timber  is  not  so  hable  to  shrink 
and  ia  less  susceptible  to  dry  rot,  yet  it  possesses  the  disadvantage 
of  decreasing  the  strength  of  the  wood,  and  produces  a  hard  veneer 
on  the  surface  which  does  not  readily  permit  of  the  thorough 
evaporation  of  the  internal  juices, 

Water  seasoning  is  resorted  to  for  shipbuilding  purposes,  but 
the  balks  must  be  totally  immersed.  Tlie  internal  juices  of  the 
aap  which  are  more  inclined  to  decay,  are  supposed  to  be  more 


i 


90  SHIPS'  BOATS 

efficifintly  remnvinl  by  tliis  method  tlmn  by  adopting  the  ordtnaiy.! 
precautions. 

Detects  seen  alter  Conversion. — During  the  process  of  ^ 
Beaaonin^,  defects  will  bec-ome  magiiified.  The  preseHce  of  cwp 
shakes  (Fij;,  27}  are  attributed  to  the  result  of  sudden  chaugea  of 
atmosphere,  producing  a  detrimental  effect  on  the  sap  and 
checldng  the  normal  growth ;  they  usuall}  take  the  same  shape 
as  the  annual  rings, 

Star  and  Heart  Shakes  (Fig.  28)  generally  occur  at  the  ends  of 
a  log  and  are  the  results  of  the  timber  drying  quicker  at  the 
exposed  extremities.  Where  trees  have  been  growing  on  loose 
soil  the  timber  at  its  centre  appears  to  be  split  up  with  shakes 
and  cleft«.     Material  in  this  condition  i.s  said  to  be  "  Quggy.'' 

Rind  Galls  (Fig.  29)  are  produced  through  injuries  to  the  tree 
by  broken  branches  which,  on  being  exposed  to  the  atmosphe 


become  rotten.  The  injury  ia  subsequently  covered  up  by  the 
natural  growth  of  the  tree. 

Resin  (rails  arc  very  difficult  to  discover  until  the  timber  b 
cut  up  into  planks  ;  they  often  occur  in  larch.  No  mercy  should 
be  shown  to  the  plajika  in  which  these  galls  are  discovered  and  they 
should  be  immediately  removed  from  the  boat.  The  effect  of 
the  sun  quickly  opens  out  the  defect,  and  caulking  a  thread  of 
cotton  intji  the  cavity  only  accentuates  the  trouble. 

Black  Knots. — One  cannot  expect  to  secure  larch  without 
knots,  and  the  inspector  must  use  his  own  judgment  in  dealing 
with  the^e.  Sometimes  a  good  doubling  is  of  more  value  than 
removing  the  plank. 

Upsrls  are  defects  which  produce  a  separation  in  the  grain  of 
the  wood, 

Faxiness  particularly  applipji  to  nal(  which  is  grown  on 
awanipy  ground  ;  it  gives  a  reddish  colour  to  the  wood  near  the 
heart,  which  ia  clejir  evidence  of  approaching  decay. 

Worm  Holes, — Thcae  very  often  occur  in  teak  and  mahogany. 


I 


TIMBER:  CONVERSION,   ETC. 


91 


Thoae  in  the  former  material  are  very  quickly  discovered,  but  in 
mahogany  a  very  close  inspection  is  needed  to  locate  them  ; 
they  are  usually  about  the  size  ()f  ao  ordinary  pin  head. 

Disease. ^The  sap  which  rises  through  tho  tree  contams  an 
acid  and  if  the  flow  is  checked  by  atmospheric  effect  or  is  left  to 
itself,  it  quickly  ferments  and  in  the  ripe  condition  generally 
becomes  infected  by  any  fungus  growth.  This  growth  usually 
appears  at  the  base  of  the  tree,  feeding  on  the  vegetable 
substance  of  the  sap,  pieroinj^  the  cells,  and  eventually  turning 
the  timber  into  the  condition  of  a  sponge.  Other  trees  in  the 
immediate  vicinity  of  the  infected  timber  very  quickly  become 
contaminated. 

Dry  aiid  Wet  Rot  are  two  diseases  whicii,  having  obt-ained  a 
hold  on  timber,  are  very  injurious  to  the  material  and  difficult  to 
eradicate.  There  is  a  difference  between  the  two,  the  latter 
being  produced  by  putrification  caused  by  constant  cjcposure, 
but  dry  rot  ia  considered  to  be  the  more  dangerous  of  the  two, 
and  if  it  attacks  the  portions  of  boats  which  are  not  exposed  to 
view,  serious  trouble  may  be  caused  before  discovery. 

Sound-looking  timber,  even  when  cut  up  into  planks,  may 
have  bec-ome  infected  with  dry  rot  by  coming  into  contact  with 
diseased  wood,  but  there  would  be  no  evidence  to  the  nalied  eye 
until  the  spores  of  the  fungus  began  to  germmate,  and  it  requires 
certain  conditions  for  this  to  be  brought  about  before  the 
mycelium  is  developed.  A  still,  warm,  and  damp  atmosphere 
very  quickly  aggravates  this  trouble. 

There  is  no  doubt  that  the  initial  cause  of  the  rapid  spread 
of  dry  rot  is  the  imperfect  seasoning  of  timber,  accelerated  by 
the  laokof  proper  ventilation.  The  fungus  filarpeat,  or  mycelium, 
when  it  attacks  the  heart  wood,  is  very  difficult  to  locate,  unless 
the  wood  is  seen  to  swell  and  the  change  of  colour  becomes  evident 
on  the  outside  surface. 

An  inttiresting  case  came  imder  the  notice  of  the  writer  a  few 
years  ago.  A  large  sailing  yacht  was  drawn  up  on  one  of  the 
slips  on  the  (.!lyde  for  surveying  purposes  and  slight  repairs ; 
when  making  adjustments  to  some  securities  of  the  keel  it  was 
found  that  dry  rot  was  present,  but  the  superficial  indications 
were  only  slight.  Eventually,  after  further  investigation,  it  was 
discovered  that  tlie whole  of  thewood  keel  was  rotten,tlie  internal 
portion  of  which  could  actually  be  removed  with  the  aid  of  a 
spade.  There  was  no  lack  of  money  in  providing  every  faoihty 
to  prodnce  a  first-cla«a  article,  hut  apparently  the  builders  had 
been  deceived  in  the  quality  of  the  material  they  were  using,  and 


92  SHIPS'  BOATS  ^^^1 

the  circutustances  only  went  to  prove  how  difficult  it  is  to  dtscoverfl 
the  trouble  in  ita  initial  stages  of  germination. 

When  the  surface  of  materia!  ia  attacked  by  wet  rot  and  the  I 
conditions  are  ripe  for  propagation,  the  evidence  ia  quickly  seen 
in  the  form  of  mildew  which  can  be  wiped  off  with  the  finger. 
When  pontoon  lifeboats  have  been  constructed  during  the  early 
winter  and  laid  on  one  aide  in  the  boatyai'd  until  requisitioned 
by  a  vessel,  it  is  not  an  uncommon  occurrence  to  discover  the  , 
existence  of  the  disease  in  opening  out  the  hull  for  final  inspection 
before  delivery,  I 

It  is  not  intended  in  thia  section  t«  investigate  any  chemical  | 
theory  aa  to  the  cause  of  the  disease,  but  it  is  very  evident  from  i 
practical  observation,  that  the  presence  of  shavings,  sawdust, 
etc..  left  by  the  boatbuilders  in  the  lockers  at  the  ends  of  the 
boat  and  behijid  the  tank  cleading.  provide  ready  opportunity 
for  distributing  and  carrying  the  fungus  of  dry  rot  should 
the  material  be  in  any  way  impregnated  with  the  disease.  In 
consideration  of  these  difficulties  it  is  very  essential  that  masters 
of  vessels  should  see  that  buoyancy  tanks  are  periodically  taken 
out  and  the  inside  of  the  planking  and  timbers  thoroughly  dried 
and  repainted.  Warmth  and  moisture  acting  in  conjunction 
with  one  another  are  very  active  agents  in  producing  decay; 
although  timber  of  certain  species,  constantly  immersed  in  water,  , 
ia  less  snace.ptible  to  the  extension  of  diseaae,  as  many  readers 
may  have  toimd  from  practical  experience  in  surveying  the  hull 
of  wooden  vessels,  more  especially  in  way  of  the  bilges. 

The  weight  of  timber  infected  with  dry  rot  is  greatly  reduced, 
and  the  superficial  evidence  of  the  disease  gives  one  the  impression 
that  the  material  has  been  burned,  and  pieces  cut  from  the  infected 
part  are  very  brittle  and  if  rubbed  between  the  fingers  can  be 
blown  away  like  dust. 

Much  has  been  written  on  the  subject  by  experts,  and  com- 
parative experiments  carried  out  aa  to  the  effect  of  dry  rot  on  ■ 
various  types  of  timber,  but  provided  the  timber  has  not  been 
infected  with  the  disease  before  feUing,  it  is  very  evident  from  the 
results  of  practical  observation  that  if  the  material  ia  thoroughly 
seasoned  and  kept  dry  by  periodical  ventilation,  it  ia  proof 
against  dry  rot. 

Trees  are  damaged  sometimes  by  injury  to  the  bark,  and  by 
the  breaking  off  of  branches  due  to  their  exposed  position,  or  by 
the  effects  of  frost  bite.  The  injured  parts  are  thus  laid  bare 
to  the  attack  of  parasites  which  give  off  a  secretion  and 
discolour  the  timber,  eventually  destroying  the  tree. 


TIMBER:    CONVERSION,   ETC.  93 

The  liii'cli  is  vury  liable  to  a  particular  kind  of  canker  disease 
and  if  the  bark  at  any  time  becomes  injured,  tliis  Ehould  be 
carefully  covered  up  until  tlie  natural  growth  of  the  tvee  preveute 
any  further  attack. 

Preservation. — In  the  days  of  wood  shipbuilding  the  question 
of  increasing  the  laating  qualities  of  timber  was  one  of  great 
importance.  Many  experiments  were  carried  out  and  much 
attention  devoted  to  the  various  methods  calculated  to  make  the 
material  impervious  to  the  effects  of  the  weather,  but,  whatever 
composition  or  treatment  was  used  in  the  application  of  chemical 
impregnation,  it  was  essential  in  the  first  place  for  the  timber  to 
be  thoroughly  seasoned. 

Salt  was  worked  between  tJie  outer  and  iimer  planks  for  the 
purpose  of  preservation  and  extending  the  life  of  the  vessel.  In 
recent  years  a  system  of  impregnating  the  timber  with  an  in- 
jection of  distilled  coal  tar,  under  pressure,  has  been  iu  operation 
with  excellent  results  and  calculated  t*)  add  to  the  lasting  quahties 
of  the  wood  exposed  to  the  changes  of  atmospliere.  No  such 
methods  are  resorted  to  in  the  treatment  of  material  for  ordinary 
ships'  boats,  but  in  the  construction  of  motor  boats,  the  wood 
casing,  watertight  bulkheads,  and  surrounding  structure,  is  very 
often  chemically  treated  in  order  to  make  it  fireproof. 

The  precautions  which  are  taken  iu  dealing  with  the  preserva- 
tion of  the  wood  during  and  after  the  construction  of  ships'  boats 
are  referred  to  in  Section  D  of  Part  VII. 

It  is  not  considered  out  of  place  in  this  section  to  make 
reference  to  the  "  Oxylene"  process  of  producing  non-inflavimabie 
Umber.  The  writer  is  indebted  to  the  Timber  Fireproofing  Co., 
Ltd.,  of  Townmead  Road,  Fulhara,  S.W,,  for  a  description  of  this 
particular  treatment. 

The  British  Admiralty  have  for  several  years  kept  this  subject 
under  close  observation  with  a  view  to  obtaining  the  must  snitahlc 
timber  which  ia  "  Hame-proof,"  Wood  in  a  war  vessel  is  kept 
down  to  the  irreducible  minimum,  but  it  cannot  be  obliterated 
altogether  in  the  construction,  and  the  use  of  non-infiammablc 
wood  could  with  advantage  be  used  to  a  much  larger  extent  in 
the  construction  of  State  rooms,  etc.,  in  passenger  vessels  of 
the  Mercantile  Marine  Service.  The  matter  is  one  worthy  of 
further  consideration  in  view  of  the  recommendations  and 
regulations  of  the  International  Convention  for  the  Safety  of 
Life  at  Sea. 

Material  treated  by  the  "  Oxylene "  process  ia  extensively 
used  in  the  construction  of  motor  boats  and  it  is  understood 


M  SHIPS'  BOATS 

tLat  u  boat  hum  been  bitilt  tkioughout,  as  an  experiment,  with 
wood  subjected  to  this  method  of  treatment. 

Timber  jiubjected  to  this  process  is  enclosed  in  a  lar^c  iron 
cylinder  aud  submitted  to  a  steaming  and  vacuum  treatment  hj 
which  the  sap,  air,  and  moisture  in  the  poies  of  the  wood  are 
removed  and  vaporised.  The  wood  is  then  impregnated  under 
hyUrauhc  pressure,  with  a  solution  of  antipyrine  chemicals, 
which  Teplaces  the  elements  driven  out  by  the  preliminary  treat- 
ment. This  chemical  solution  is  considered  to  be  preservative, 
antiseptic,  and  non-corrosive.  It  therefore  does  not  injure  metal 
brought  into  contact  with  the  wood. 

The  material  is  subsequently  placed  in  spetdaily  constructed 
dry  kilns,  where  the  water  of  the  solution  is  finally  dried  off, 
the  chemicals  in  minute  crystal  form  remaining  permanently 
embedded  in  the  fibres.  When  heat  ia  applied  to  wood  treated 
i)y  the  "  Oxylene  "  process,  the  crystals  iu  the  wood  expand  and 
form  a  glassy  coating  which  excludes  the  oxygen  in  the  air  and 
prevents  its  combination  with  the  wood,  without  which  com- 
bustion is  impossible.  The  greater  the  heat  the  mure  the  crystals 
expand,  and  although  in  time  their  chemical  actitm  is  exhausted 
and  the  wood  becomes  charred,  fresh  crvatals  take  their  place, 
80  that  even  when  the  wood  becomes  e-oiupletely  charred  through, 
no  flame  will  be  generated.  This  theory  has  been  substantiated 
by  tests  on  an  extensive  scale,  and  from  samples  submitted  to 
the  writer,  it  became  quite  evident  when  placed  on  a  coal  fire 
that  they  were  absolutely  "  flame-proof." 

Seleotfon. — When  selecting  timber,  inspection  is  made  of  the 
butt  end  of  the  log,  which  should  be  close,  sohd,  and  sound  ;  the 
to]i  is  then  examined  to  see  if  it  corresponds  with  the  butt  end. 

DiSerences  iu  sound  will  indicate  the  presence  and  position 
of  good  and  unsound  timber,  the  perfect  wood  giving  a  sohd 
and  sharp  sound  when  struck  with  a  hammer,  white  the  decayed 
portions  produce  a  dull  sound,  and  the  presence  of  inteiiial 
shakes  will  give  the  impression  of  the  material  being  hollow. 

An  old  dodge  is  to  place  a  watc^h  against  tlie  butt  end  of  the 
log,  the  ticking  of  which  is  plainly  to  be  heard  at  the  other  end 
if  the  material  is  sound. 

A  surface  inspection  is  made  for  the  existence  of  rind  galls, 
spooginess  at  the  pitii  which  denotes  old  age,  decayed  knots 
and  discoioration  at  the  ends  which  indicate  decay. 

Straightness  of  grain  is  essential  for  material  wliich  is  to 
be  appropriated  for  the  constnictiuu  of  ships'  boats,  except 
where  crooks  are  reipured. 


I 


I 


TIMBKR:  OOSVEHSION,  ETC. 


96 


I 


Bright-looking  timber  in  superior  in  quaiity  to  the  dull,  aud 
that  which  is  smooth  in  working  ia  better  than  the  rough  or 
woolly. 

If  the  timber,  when  passed  through  the  saw,  has  a  tendency 
to  clog  the  teeth,  it  is  evidence  of  unauitabiUty.  If  when  freshly 
cut  it  gives  ofi  an  objiictionabie  odour,  it  is  invariably  a  sign 
of  the  presence  of  decay. 

Strength. — Particuhir  attention  is  paid  to  the  various  species 
of  timber  to  permit  of  the  maximum  amount  of  strength  being 
incorporated  into  the  structure  of  a  ship's  boat.  The  scantlings 
of  material  given  in  Table  XIV,  have  been  drawn  up  having  in 
view  the  great  streaaes  to  which  a  boat  is  subjected  when  being 
"lowered  into  the  water  with  the  full  complement  of  persons  on 
board. 

The  lemile  ati'ength  of  material  ia  the  quality  to  resist  a 
cohesive  force  or  weight  that  tends  to  pull  it  asunder  in  the  direction 
of  its  length. 

All  material  worked  in  a  fore-and-aft  direction  to  maintain  the 
loQgitudtnal  streugtb,  should  combine  toughness  and  Jlex^lity, 
thettu  being  the  quaUtios  which  combine  the  greatest  degree  of 
atiength  and  elasticity  against  fracture. 

Topre8erveatraightnoss,a  largo  meaaureof  stiffneji»i&  necesaury, 
and  this  can  be  measured  by  what  is  teitned  the  modulus  of 
ela^iciljf,  which  ie  a  standard  from  which  tiie  elasticity  of  one 
material  can  be  compared  with  another.  It  b  the  measure  of 
the  force  or  weight  whicli  is  required  to  extend  a  bar,  one  inch 
square,  to  double  its  original  length. 

In  Tabic  XIII.  a  comparison  b  made  of  the  strength  and 
elasticity  of  different  woods  used  in  boatbuilding  and  ship- 
building. 

Reference  b  made  in  Section  B  to  the  qualities  of  the  various 
species  of  timber,  and  should  be  read  in  conjunction  with  the 
latter  part  of  Section  C  of  Part  JI.,  deaUng  with  tiio  strength  of 
ships'  boats. 

Measurement  of  Timber. — There  are  ceitain  standards  of 
meaaureiijeiit  appliwl  to  timber  when  aold  by  the  iiieit'.hant. 

A  loud  contains  50  cub.  ft.  of  hewn  or  sawn  timber,  and 
40  cub.  ft.  of  imhewn  timber. 

A  gquare  b  used  generally  when  selling  boarding,  and  b  a 
superficial  measurement  and  contains  100  sq.  ft. 

St.  Fetersburgh  Standard.— i:\aa  b  a  standard  which  b  in 
general  use  in  Great  Britain  and  more  particularly  appUed 
to  the  soft  woods  such  as  fir  and  pine.     One  standard  contains 


96 


SHIPS'  BOATS 


165   cub.   ft.   or   720   lin.    ft.    of   planks   or   deals   of    11   in: 
by  Sin. 

For  weights  of  principal  woods  used  in  boatbuilding,  reference 
must  bo  made  to  Part  IX. 


TABLE  XIU. 
STBSMam  AND  ELASTiciry  ovTdibeb. 


Aah,  Engliah  .      .      . 
Afh,  American 
Cedar,  Cuba    .      .      . 
Elm,  English .      .      . 
Kim,  Canada  ■ 
Fir,  Riga  .      .      .      . 
Fir,  SpruDo,  Caiiudu  . 
Qieeiiivjart,  Deiuoruin 
Hombeam,  EoRlitili  . 
Jurrah,  Anatnuiaii 
Kauri,  New  Ze«i  land  . 
Laroh,  Busai&n 


ToDH  iier  Hq.  111. 


3'9  «'8   8'0l  400 

2-9  3-7  I  —  — 

1'3  3'2,l-2  -AM 

20  2-fl I  —  — 

1-8  2-7,3'8  730 


'  Mubogauy.  Cuba  . 
MBbogany.  HunduraB 
Mahugany,  Mi^xican  . 
Uak,  Englisli  .      .      . 
UbIe,  Ruiuian  . 
Oak,  Spanieh  .      .      . 
Uak,  American  Whito 
Pin<>,  Red,  Canada    . 
Pine,  Yellow,  Canada 
Pine,  Pitob,  Ami^ricaD 
Sabicu,  Cuba  .      . 
Teak,  Burmah      .      . 


HarUngs  ol  Foreign  Timber. — Each  country  has  its  own 
particular  method  of  branding  or  marking  the  timber  for  identi- 
fication purposes,  but  the  following  list  will  give  the  principal 
,   sources  of  supply  :— 

Canada. — The  timber  is  stencilled  with  the  traders'  marks  in 
black  and  white. 

United  Slates. — The  marks  are  made  in  red  chalk  ou  the 
sides  of  the  balks. 

Russia. — The  ends  of  the  timber  are  branded  or  stamped. 
Timber  grown  in  the  Imitate  forests  had  the  crown  stamped  on  the 
ends.     Hence  the  timber  is  known  as  "  crown  deals." 

Sweden. — The  letters  are  stencilled  in  red  on  the  ends. 

Norway. — The  markings  are  made  in  a  similar  way  to  that 
of  Sweden  except  that  the  colouring  is  blue. 

Qermany. — The  letters  are  cut  in  on  the  sides  of  the  timber, 
new  tiie  middle  of  the  length. 


I 


PRINCIPAL  WOODS  USED  IN  CONSTBUCTION 

SECTION  B.— PRINCIPAL  WOODS  USED  IN  THE  CON- 
STRUCTION OF  BOATS,  AND  THEIR  RESPECTIVE 
QUALITIES 

'  One  of  the  difficultiea  which  is  conimon  to  all  who  have  any 
coimection  with  the  timber  trade,  is  the  confusion  of  different 
names  applied  to  the  same  species  of  wood,  but  grown  in  different 
localities,  e.g.  Baltic  redwood  and  yellow  deal,  Oregon  pine  and 
Douglas  fir,  yellow  pine  and  American  white  pine.  These 
differences  particularly  apply  to  imported  timber. 

There  is  a  great  similarity  between  certain  woods,  which 
makes  it  very  difGcult  for  the  inspector  to  identify  the  materials 
when  they  are  seen  apart. 

It  requires  aa  expert  to  tell  the  difference  between  wych  and 
English  elm,  beech  and  birch,  also  hickory  and  ash. 

In  dealing  with  boat  construction  it  is  very  essential  to  use 
woods  whose  quahtiea  are  best  suited  for  the  particular  purpose 
required. 

The  various  species  of  wood  worked  into  the  hull  of  ships' 
boats  are  referred  to  La  detail  in  the  following  order  :— 

•  English  Oak. — Where  stiffness  and  durability  are  required 
in  lifeboats,  together  with  the  quality  fur  resisting  climatic 
changes,  as  in  lieadwooUs,  stem,  stempost  and  keel,  English 
oak  comparer  very  favourably  with  the  very  best  of  hard  woods. 
It  is  hard,  tough,  strong,  and  elastic  ;  the  grain  is  usually  straight, 
uniform,  and  free  from  kiiots. 

The  annual  rings  are  ck)3e  together  and  distinct. 
The  medullary  rays  running  at  right  angles  ta  the  annual 
rings  can  be  clearly  seen,  and  when  cut,  produce  a   very   fine, 
silky  appearance  in  the  surface  of  the  wood. 

Other  species  of  oak  are  grown  in  Austria  and  America,  but 
are  considered  inferior  to  (he  English  quality,  being  much 
softer. 

■  Oak  tends  to  warp  and  twist  in  the  process  of  seasoning  and 
deteriorates  at  the  ends,  imless  the  timber  is  placed  \mder  cover, 
Vrhich  diminishes  the  difficulty.  It  ct^mtains  a  powerful  gallic 
■cid,  which  corrodes  iixin  fastenings  and  tends  to  rot  in  way  of 
theee  securities.  For  this  reason  it  is  very  essential  that  all 
iron  bolts  should  be  heavily  galvanized. 

Oak  is  not  adaptable  fur  cutting  into  small  scantlings  for  boata' 
^1  apper  or  sheer  strakas,  or  the  inner  gunwale  of  the  box  shape, 
^Bowing  tu  its  tendency  to  split  when  under  ten.'iioa  and  exposure 


96  SHIPS'  BOATS  ^^M 

to  the  weather.  This  is  purely  an  expreflsion  of  opinion  and  t^e 
writer  will  probably  be  opposed  by  those  who  adhere  to  the 
practice  of  working  in  oak  planking; ;  however,  it  is  considered 
there  are  limitations  to  the  use  of  this  wood,  and  it  can  be  beat 
employed  in  the  solid  combinations  forming  the  frame  of  the 
boat. 

Immediately  the  stem  and  stempost  have  been  trimmed 
and  scarphed  to  the  keel,  they  shoidd  be  well  coated  with  boiled 
linseed  oil,  varnish,  or  paint,  as  a  means  of  protection  from  the 
weather. 

In  selecting  oak,  care  should  be  exercised  to  avoid  all  material 
which  approaches  a  light  brown  or  red  colour,  to  guard  against 
"  foxiness,"  a  disease  which  has  already  been  referred  to  in  the 
previous  section. 

English  oak  is  used  for  stems,  stemposts,  aprons,  deadwoods, 
solid  gunwales,  keels,  keelsons,  and  thwart  knees. 

English  Elm  is  a  very  difficult  wood  to  work,  being  cross- 
grained,  but  verj'  tenacious  and  not  easily  split. 

Owing  to  the  absence  of  longitudinal  fibre  and  its  power  to 
resist  the  influence  of  weather,  it  is  largely  employed  in  the 
manufacture  of  lifting  blocks.  The  timber  is  very  durable  if 
constantly  immersed  in  water  and  for  this  reason  the  planks  of 
woiKlen  vessels  below  the  water-hne  are  usually  of  English  elm. 

Wliere  there  is  a  tendency  for  water  to  accumulate  and  for 
the  details  of  combinations  to  become  exposed  to  alternate  wet 
and  dry  atmospheres,  English  elm  is  considered  to  be  of  less 
value  than  English  oak  ;  consequently  it  is  advisable  to  have 
the  deadwoods  made  from  the  latter  material. 

English  elm  twista  and  warps  a  great  deal  during  the  procesB 
of  seasoning.  It  has  a  very  distinctive  reddish  brown  colour 
and  the  piesence  of  sap  is  very  marked  by  its  yellow  appearance. 
It  is  used  for  the  backboards  of  sqnare-stemed  boats  and  no 
material  is  better  suited  for  rudders  than  English  elm. 

During  the  war  period,  when  the  difficulty  to  obtain  Eaglish 
oak  or  rock  elm  of  suitable  length  was  very  acute,  Kngliah  elm 
was  used  for  gunwales  by  slightly  increasing  the  scantlings. 

Wyoh  Elm.— There  is  a  great  similarity  in  appearance  between 
wych  and  English  elm,  the  former  being  of  finer  grain  with 
greater  length  of  longitudinal  fibre.  The  difference  between  tie- 
two  is  more  noticeable  in  the  growing  trees,  where  the  leaves  of 
the  wych  elm  are  much  smaller  and  possess  a  smoother  surface 
than  those  of  the  English  elm.  Its  use  for  boatbuilding  is 
practically   confined   to    Admiralty   work,    but   sometimes    in 


I 
I 


PRINCIPAL  WOODS  USED  IN  CONSTRUCTION    99 

latch  boata  the  garbuards  and  adjacent  strakes  of  planking  are 
of  wych  elm ;  it  serves  the  purpose  well  in  this  position  and 
provides  a  RfwKl  solid  caulking  seam  at  the  keel. 

Canadian  ot  Rock  Elm. — This  wood  is  well  adapted  for  iiae,  and 

extensively  employed,  in  boatbuilding  owing  to  its  close  straight 

.  grain  and  freedom  from  knots  ;  it  is  very  teoscious  but  wonder- 

I  ftilly  flexible   and   possesses   few   superior  woods   for  timbers, 

keel,  hog-piece,  and  gunwales. 

Great  Britain  depends  entirely  on  the  importation  ot  this 
timber  from  America  for  supplying  the  increasing  necessities  of 
the  boatyards  and  shipyardB. 

Teak. — This  is  considered  to  be  the  very  best  quality  of 
wood  for  the  construction  of  the  highest  standard  of  ships'  boats. 
It  successfully  resists  the  action  of  water,  stands  the  climatic 
changes  better  than  any  other  wood,  is  very  durable  and  elastic, 
shrinks  little,  and  is  free  from  objectionable  knots.  Care  should 
be  exercised  to  watch  for  small  worm  holes. 

One  drawback  to  hfeboats  constructed  of  teak,  is  the  increase 
of  weight  aa  compared  with  yellow  pine  and  larch,  but  the  ad- 
vantages associated  with  the  use  of  this  wood  greatly  outweigh 
t^e  disadvantage. 

Although  the  cost  of  production  is  greater,  the  additional 
outlay  is  more  than  compensated  by  the  length  of  time  the 
boats  wiU  last. 

The  quality  of  the  material  is  such  that  the  weight  is  lessened 
I  to  some  extent  by  the  admissible  thinning  of  scantUnga  below 
I  those  of  larch  or  other  soft  woods. 

Most  of  the  leading  shipping  companies,  whose  vessels  sail 
through  tropical  waters,  insist  that  their  lifeboats  shall  be 
constructed  of  teak  or  mahogany. 

It  stands  to  reason,  that  timber  grown  in  northern  climates, 

^  such  as  larch  and  English  ur  wych  elm,  are  unsuitable  t'O  witli- 

I  Btand  extremes  of  temperature,  and  it  is  the  considered  opinion  of 

I  many  experts,  backed  itp  liy  the  experience  of  masters  of  vessels, 

[  that  all   foreign-going   vessels  should  be  equipped  with   boat« 

[  constructed  entirely  of  teak  or  mahogany,  preferably  the  former. 

The  timbers  of  boats  constructed  of  eitlior  teak  or  mahogany 

should   be  made  from  American  rock  elm,  as  the  first-named 

woods  are  not  adaptable  fur  the  purpose.     Tlie  writer  lias  seen 

boatbuUders  endeavouring  to  satisfy  the  requirements  of  some 

t owners  desiring  teak  timbers,  with  the  result  that  more  timbers 
were  spoiled  than  were  actually  worked  into  the  boat. 
Teak  varies  greatly  in  weight,  from  41  to  53  lbs,  to  the 


I 


t 

I 

t 
c 

I 


i 


100 


SHIPS'   B0AT8 


cub.  ft.,  depending  upon  the  position  ot  the  plank  cut  in  relatioD 
to  tlie  heart  wood.  It  seasons  very  quickly  and  is  imported 
from  Malabar,  Java,  Ceylon,  and  Moulniein.  It  possesses  an 
uily  infiredient  which  affords  protection  to  the  iron  fastenings. 

Mahogany. — This  timber  is  grown  in  the  West  Indies,  West 
Coast  of  Africa,  and  in  America  around  the  Bay  of  Honduras, 
The  annual  rings  are  verj-  distinct ;   like  teak,  it  is  verj'  durably  ■ 
shrinks  but  little  and  does  not  twist  or  warp  readily. 

Treea  which  are  grown  in  swampy  positions  produce  timbei 
of  an  inferior  quahty,  which  becomes  porous  and  light, 

The  quality  of  mahogany  varies  considerably  and  it  therefoi 
becomes  essential  to  exercise  the  greatest  care  in  selecting  thtsl 
material  for  use  in  boatbuilding. 

Spanish    nmhogany  is  distinguished  from  Honduras  by  its  4 

■   closer  grain  and  darker  colour.     It  is  colder  to  the  touch  and  1 

possesses  a  silky  texture  with  white  specks  in  it,  while  the  specks  I 

in  Honduras  mahogany  are  black. 

Spanish   mahogany  comes   from   Cuba,  Trinidad,   and   I 
Domingo, 

A  large  quantity  of  mahogany  is  shipped  from  the  WestJ 
fViast  of  Africa.  Lagos  is  much  about  the  same  in  colour  and  1 
as  fine  in  texture  as  the  Tabasco  tnahogany,  which  is  shipped  from  J 
South  of  Mexico,  but  is  smaller  in  size. 

Gaboon  wood  should  bo  avoided  ;  it  is  iintcli  lighter  in  colour  I 
than  the  previoiisly  mentioned  types,  resembling  that  of  teak,] 
and  very  light  in  weight. 

It  is  veiy  difficult  at  times  %o  tell  the  difference  between  tha  1 
various  species  of  mahogany. 

In  good  class  boat«,  mahogany  is  used  for  planking  and  ia'l 
extensively  eniploye<l  for  the  double  skins  of  lifeboats  of  Class  II. 
and  motor  boats. 

When  inspecting  mahogany  planking  previous  to  painl^,  ' 
one  needs  to  carefully  watch  for  small  pin  holes  produced  by 
minute  worms.  In  the  process  of  splitting  up  the  planks,  the 
saw  fills  up  these  worm  holes,  which,  therefore,  become  difficult 
to  discover  before  the  boat  is  water-borne.  The  best  remedy 
for  this  dp.fi'ct  appears  to  be  the  insertion  of  small  soft  wood 
plugs,  usually  made  of  yellow  pine. 

Beech,— There  are  limitations  to  the  use  of  this  material  in 
boatbuilding,  although  it  is  tougher  than  English  oak  and  yvry 
durable  if  constantly  immersed  in  wat<er,  yet  when  exposed  to 
damp  conditions  it  Koa  a  teudonoy  to  rot  and  it  is  therefore 
advisable  to  avoid  it«  use  in  rnrming  the  uunbinations. 


PRINCIPAL  WOODS  USED  IN   CONSTRUCTION    101 

Plane  Tree  reeemblea  beech  very  much  in  appearance  and 
nature;  it  also  possesses  the  same  features  which  make  it 
undesirable  for  extensive  use  in  the  construction  of  ships'  boats. 

Ash,— Whore  toughness  and  elasticity  are  required  there  are 
few  woods  which  surpass  ash.  It  is  grown  in  most  parta  of 
Europe  and  America. 

A  difference  of  opinion  exists  among  boatbuilders  as  to  the 
efficiency  of  timbers  made  from  ash,  for  the  material  possesses  the 
disadvantage  that  when  exposed  to  alternate  dryness  and  moisture 
it  soon  rot^  and  in  this  respect  is  not  so  durable  as  American 
elm  for  the  purpose  referred  to. 

Ash  will  stand  sudden  and  ^reat  stress,  and  is  therefore  well 
adapted  for  tt>wing  bollards  and  fco  serve  as  a  substitute  for 
English  or  ^Vmerican  rock  elm  in  forming;  gunwales. 

Young  trees  produce  timber  of  greater  strength  than  if  allowed 
to  grow  to  maturity. 

The  groat  bulk  of  oars  are  made  of  ash. 

Larch. ^Ninety  per  cent,  of  ships'  boats  constructed  in 
Great  Britain  have  larch  planking.  It  grows  in  most  of  the 
northern  districts  of  Europe  and  the  quality  of  the  trees  culti- 
vated in  the  central  and  northern  counties  of  Scotland  is  ex- 
ceptionally line.  It  is  straight  in  grain,  tough,  and  very  durable, 
but  shrinks  quickly  with  a  tendency  to  warp,  so  that  care  should 
be  exercised  to  see  that  the  material  is  thoniughly  seasoned 
before  being  worked  into  the  boat. 

Larch  can  be  secured  in  fairly  long  lengths,  but  the  timber 
grown  in  Great  Britain  usually  contains  more  knots  than  that 
which  is  import«d  from  Russia  and  other  Nortlieni  porta,  due 
to  the  fact  that  the  trees  in  the  British  Isles  grow  with  their- 
branches  ncai-er  to  the  ground. 

The  fertile  plains  of  England  are  not  adapted  to  the  full 
dovelopmeiit  of  the  larch  ;  the  latter  needs  an  elevated,  open 
sub-soU,  with  a  clear  atmosphere. 

Since  the  year  1725,  when  the  larch  was  first  introduced  into 
the  Highlands  of  Scotland,  it  has  wonderfully  flourished.  The 
pukes  of  AtboU  have  alwa^-s  taken  a  keen  interest  in  the  pro- 
duction of  these  trees  and  some  of  the  finest  specimens  are  to 
be  found  in  the  forests  around  Dunketd,  Blair  Atholl,  and 
Mou2ie. 

The  larch  was  first  imported  fi*om  Italy,  and  it  is  of  interest 
to  note  that  during  the  lifetime  of  one  of  the  Dukes  of  Atholl, 
some  twenty-seven  million  trees  were  planted,  which  is  a  great 
contrast  to  the  lack  of  initiative  and  effort  of  landowners  of  the 


102  SHIPS'  BOATS 

present  day,  to  provide  new  wood  to  replace  the  timber  which 
is  now  being  so  speedily  used  up. 

Grood  larch  should  be  reddish  brown  in  colour  at  the 
heart  wood  and  yellowish  white  at  the  sap  wood.  The  lighter 
coloured  timber  generally  contains  more  knots  than  the  darker. 
It  cannot  usually  be  obtained  in  sufficient  width  for  use  as 
thwarts,  without  running  into  sap  wood. 

Larch  roots  make  good  thwart  knees  and  breast-hooks  for 
the  smallest  type  of  boats. 

Lifeboats  constructed  of  larch  planking  are  very  strong  and 
durable,  provided  they  are  carried  on  vessels  which  are  not 
trading  through  the  tropics. 

It  is  very  evident  that  this  class  of  timber  cannot  be  obtained 
without  knotij,  owing  to  the  number  of  branches  on  the  tree. 
Some  of  the  branches  get  broken  at  the  tnmk  and  produce 
objecticmable  black  knotij,  which  are  not  ''  well-collared "  or 
firmly  united  to  the  surrounding  timber.  It  is  therefore  essential 
that  all  knots  in  the  planking  should  be  carefully  doubled  before 
timbering,  the  doublings  being  well  bedded  in  white  lead  paint, 
secured  under  the  timbers  by  copper  fastenings  clenched  over 
rooves.  The  practice  of  sim[)ly  securing  the  knots  by  the  head 
of  a  nail,  having  the  point  plied  over  on  the  inside  of  the  planking, 
should  be  strongly  condenmcd. 

The  larch  tree  is  very  susceptible  to  a  peculiar  disease  of  its 
own,  in  the  form  of  a  canker,  produced  by  summer  frost,  which 
interferes  with  the  free  circulation  of  the  sap  and  forms  a  weak 
spot  on  the  trunk: 

Cedar. — There  is  not  much  call  for  the  use  of  this  material  in 
the  construction  of  ships'  boats  in  Great  Britain. 

Many  trees  grown  in  various  countries,  particularly  in  America, 
are  described  under  tlie  name  of  cedar,  hut  are  inferior  in  quality 
and  do  not  bare  comparison  with  the  cedars  on  Mount  Lebanon 
in  Syria,  referred  to  in  Biblical  history,  whose  magnificent 
grandeur  and  beauty  called  forth  so  nmcli  comment  from  the 
Prophets  of  ancient  times.  Mount  Lebanon  is  some  10,000  feet 
high  and  the  cedars  grew  at  an  altitude  of  about  8000  feet  above 
the  level  of  the  sea,  but  verv  few  of  these  trees  are  to  be  found 
at  the  present  time. 

The  cedars  of  Great  Britain  and  Western  countries  are  of 
a  softer  and  more  brittle  nature  than  the  material  already 
referred  to. 

The  red  cedar  is  grown  extensively  in  the  United  States  of 
America,  is  fine  and  straight  in  grain,  fairly  durable  and  light 


PRINCIPAL  WOODS   USED  IN  CONSTKUCTION     103  ■ 

in  weight.  It  is  from  the  red  cedar  that  we  secure  the  timber 
fnr  the  manufacturt;  of  lead  pencils  and  is  little  used  in  ship  and 
boatbuildinir.  The  codar  that  is  worked  into  the  construction 
of  racing  craft  and  boats,  where  lightness  is  of  essential  value, 
comes  from  the  \\'est  Indies  aad  Central  America,  the  same 
districts  which  supply  Great  Britain  with  mahogany. 

Californian  Redwood.— This  matetial  has  been  sometimes 
usedjor  side  se^tta  and  stowing  chocks,  but  it  does  not  appear  to 
be  able  to  resist  the  action  of  the  weather  and  is  considered 
inferior  to  pit^Ji  pine.  When  pressure  ia  applied  to  the  surface 
the  material  shows  every  mark. 

Cypress. — The  common  cypress  grows  in  Asia  Minor  and 
Persia ;  it  is  extremely  light,  very  durable  in  certain  situations 
and  was  used  by  the  ancient  Egyptians  for  making  coSins, 
The  timber  that  has  a  greater  commercial  value  in  Great  firitaln 
comes  from  the  swampy  districts  along  the  rivers  and  coast-line 
of  the  southern  part  of  the  United  States  of  America. 

Louisiana  cypress  is  used  extensively  in  America  for  boat- 
building and  can  be  obtained  in  good  width  and  length,  is  free 
from  objectionable  knots,  easily  worked,  straight  in  grain,  soft 
and  light.  It  needs  to  be  carefully  used  and  the  material  should 
be  thoroughly  seasoned.  It  possesses  the  reputation  of  shrinking 
end  grain.  Where  firms  in  Great  Britain  have  the  material  in 
stock  they  make  use  of  it  for  the  purpose  of  side  seats  in  Class  I. 
open  boatfl. 

Pitch  Pine. — Pines  arc  more  resinous  than  firs  and  this  enables 
the  former  to  resist  the  action  of  water.  The  texture  is  close 
grained  and  the  material  more  durable  than  the  fir,  the  colour 
of  the  latter  usually  being  fighter  than  the  pine.  It  ia  very 
extensively  used  in  boatbuilding,  for  the  purpose  [}f  planking 
motor  boats,  keelsons,  thwarts,  and  side  seats  in  ordinary  open 
pulling  boats.  It  is  free  from  knots  and  sap  wood  and  can  be 
obtained  in  long  lengths. 

The  demand  for  this  material  in  Great  Britain  has  been 
greater  than  the  supply,  as  it  is  largely  used  for  ships'  masts, 
derricks,  and  decks. 

Oregon  Pine.— This  wood  is  imported  from  British  Columbia 
and  the  Western  States  of  America.  It  can  be  obtained  in  great 
length  and  width  and  resembles  pitch  pine  in  colour  and  general 
structure.  It«  use  is  generally  confined  to  the  portion  of  the 
structure  where  pitch  pine  is  permitted,  except  in  the  case  of 
thwarts  where  strength  is  of  importance. 

When  cut  into  small  scantling  it  is  inclined  to  open  out  when 


I 


1(H  SHIPS'   BOATS 

exposed  to  the  son.    It  can  be  secured  in  great  width  without  1 
running  into  aapwood. 

Baltic  Redwood  is  the  pine  of  the  northern  districts  of  the 
European  Continent  and,  as  the  name  sugjieats,  is  imported  from 
the  Baltic  porta,  and  also  from  Norway  and  Sweden. 

It  can  be  obtained  in  long  lengths  and  is  free  from  objectio 
able  kDota,due  to  the  lower  branches  of  the  tree  being  about  thirty 
feet  from  the  level  of  the  ground.  It  is  slightly  red  in  colour, 
tinged  with  yellow,  fairly  tough  and  durable,  is  suitable  foi 
thwarts  and  side  seats,  but  inferior  to  pitch  pine.       ' 

The  material  is  usually  imported  into  Great  Britain  in  deals 
and  planks,  and  known  in  the  South  as  the  yellow  deal. 

American  Red  Pine. — ^Vlthough  this  wood  is  inferior  to  the 
Northern  grown  timber,  it  is,  nevertheless,  of  good  quality  and, 
where  strength  and  durability  are  quahties  of  paramount  im- 
portance, is  greatly  to  be  preferred  to  the  home-grown  firs  of 
Great  Britain.  Its  uae  is  confined  to  those  portions  of  a  lifeboat 
where  Baltic  redwood  cannot  bo  obtained. 

Yellow  Plne.^Wlierc  lightness  is  of  essential  iiuportauce  in 
the  construction  of  a  boat,  or  when  the  plankiny  ia  required  to 
bo  varnished  instead  of  being  coated  with  paint,  yellow  pine  ie 
weU  adapted  for  the  purpose.  It  is  free  from  objectionable 
knots,  is  straight  in  grain,  elastic,  and  easily  worked.  The 
seams  of  the  planking  quickly  "  take  up  "  and  become  tight  , 
when  immersed  in  water. 

The  timber  is  mostly  imported  from  Quebec  and  Ontario  and 
the  nortliern  districts  nf  the  United  States  of  America, 

Wliile  Pine. — There  is  no  other  tree  which  grows  ao  freely 
and  produces  timber  so  valuable  on  poor  soils,  as  the  pine  which 
is  to  be  found  in  most  part«  of  Scotland.  Its  roots  penetrate 
the  fissures  of  rocks,  and  trees  grow  proliiically  on  the  dry 
covered  nioors,  but  they  prefer  an  elevated  situation.  Thu 
material  must  not  be  crjnfused  with  that  grown  in  the  United 
States  of  America. 

Scotch  Flr.^Uuring  the  shortage  of  home-grown  lamber  in 
Great  Britain  both  white  pine  and  Scotch  fir  were  substituted  for 
many  of  the  imported  wootls.  Their  various  characteristics  are 
veiy  similar  and  their  use  is  confined  to  side  benches,  thwarta, 
and  buoyancy  tank  cleading. 

Spruoe.—This  timber  is  obtained  from  trees  grown  in  the 
same  districts  as  the  Baltic  redwood,  but  is  much  inferior  in 
quality.  It  is  imported  in  deals  and  planks,  usually  tongued  and 
grooved.     It  b  uderior  to  red  pine,  pitch  pine,  or  redwood,  and 


THE  EQUIPMENT  OF  A  BOAT  YARD  105 

when  exposed  tu  the  weather  quickly  splits  and  is  thorufore 
unsuitable  for  side  acuta  and  thwarts.  It  very-  quickly  rubs  up 
into  splinters  after  exposure  and  wear. 

Norway  spruce  is  suitable  for  masts  of  ships'  boats. 

The  foregoing  is  a  general  description  of  the  important  woods 
used  in  the  boat  yards  of  Great  Britain.  There  are  other  timbers 
which  probably  possess  qualities  quite  equal  to  those  already 
named  and  are  suitable  for  the  purpose  of  boatbuilding,  but  the 
difficulties  of  securing  a  steady  supply  by  importation  prevent 
them  from  being  generally  adopted. 

The  United  States  of  America  has  access  to  some  of  the 
finest  timber  in  the  world  and  yet  tJie  majority  of  ships'  boats 
are  constructed  of  steel,  a  feature  which  is  probably  due  to  the 
greater  speed  at  which  the  steel  boats  can  be  completed  as 
compared  with  those  built  of  wood. 

SECTION  C— THE  EQUIPMENT  OF  A  BOAT  YARD 
The  situation  and  efficiency  of  the  plant  of  a  boat  yard  have  a 
du-ect  bearing  on  the  standard  of  workmanship  and  the  financial 
success  of  the  concern. 

The  primary  object  in  erecting  a  plant  is  to  secure  a  satis- 
factory return  for  the  monetary  outlay.  To  obtain  the  best 
results  it  is  essential  to  secure  a  situation  for  the  boat  yard  that 
is  adjacent  to  the  water  and  within  easy  access  to  the  railway. 
Yards  situated  on  the  batiks  of  the  rivers  Clyde  and  Tyne  have 
many  advantages  in  this  respeo-t. 

The  general  arrangement  of  the  plant  must  be  designed  bo 
as  to  keep  the  overhead  charges  down  to  the  irreducible  minimum. 
Each  particular  unit  or  machine  shnuld  be  carefully  considered, 
in  r^ard  to  its  relative  situation  to  the  work  it  has  t<j  perform. 

The  whole  idea  in  building  the  yard  should  be  based  on  tlie 
desire  to  reduce  manual  labour  to  the  lowest  Umit  and  substitute 
the  more  speedy  and  therefore  cheaper  methods  of  modem 
machinery-  Every  labour-saving  device  shoidd  be  welcomed  by 
the  mechanic  as  a  necessary  means  to  secure  the  highest  type  of 
workmanship  and  so  increase  the  efficiency  of  his  particular  trade. 

The  machinery,  building,  and  timber  storage  sheds  must  be 
individually  considered  in  their  relation  U^  the  actual  operation 
of  boatbuilding. 

It  is  the  general  opinion  that  the  most  satisfactorj'  method 
of  dtivinji;  wood-working  machines  is  by  electric  power,  each 
machine  being  dtiven  by  its  own  motor. 


^K    of  dti 


106 


SHIPS'   BOATS 


If  engines  and  boilers  are  utilised  they  should  be  situated  in  a  1 
separate  building  outeide  the  main  wall  of  the  mill,  to  give  greater  I 
security  from  fire  and  obviate  the  nuisance  of  duet  and  grit  j 
finding  their  way  into  the  machinery. 

fndividual  motors  for  every  machine  is  the  moat  economical  j 
arrangement  eventually,  even  if  the  initial  outlay  is  expensive. 

Wliere  several  machines  are  run  from  one  motor,  those 
which  require  the  greatest  power  should  be  nearest  the  motor 
and  the  lighter  ones  pjacetl  in  their  relative  position  as  to  the 
power  required.  j 

Good  solid  foundations  are  very  necessary  if  lull  advantage  I 
is  U)  be  obtained  from  the  value  of  the  machine.  1 

It  pays  the  individual  boatbiulder  te  erect  his  own  plant 
for  cutting  timber  from  the  log,  and  buy  direct  from  the 
feller  all  the  material  he  requires ;  otherwise,  he  cannot  be 
assured  of  well-seasoncil  wood.  He  is  also  in  a  better 
position  to  cut  to  standard  sizes,  stock  his  sheds,  and  con-  ' 
tinually  and  systematically  feed  thu  lequiroments  of  the  build- 
ing shed, 

The  question  arises  as  to  whether  the  vertical  frame  saw  j 
or  the  horizontal  band  saw  is  the  better  type  of  machine,  For  J 
ordinary  shipyard  work  undoubtedly  the  former  is  considered 
of  more  general  use,  but  for  boatbuilding,  where  the  latter  haa  J 
been  installed,  boatbuilders  are  enthueiastic  as  to  its  value  for  j 
their  particular  work.  1 

It  enables  the  machinist  to  cut  each  individual  plank  to  the  J 
required  thioloiess  ;  he  can  inspect  the  material  as  the  log  ia  cut,  1 
and  can  adjust  his  thickness  to  suit  the  character  of  the  log,  3 
especially  when  he  is  cutting  near  the  heart. 

The  writer  has  had  some  experience  on  the  C'lyde  and  other 
yards  of  Great  Britain  with  Messrs.  Kansonie's  patent  horieontal 
log-band  saw,  and  each  of  the  boatbuilders  using  this  particular 
type  of  machine  has  been  perfectly  satisfied.  Other  makes  are 
probably  on  the  market  but  the  writer  has  not  been  brought 
into  contact  with  them. 

Provided  the  operator  does  not  try  to  force  the  machine 
beyond  its  power,  the  band  mill  should  give  perfeotlj'  true  cutting 
and  is  equally  suitable  either  for  breaking  down  logs,  or  for  board 
cutting  direct  from  the  log. 

The  waste  in  saw-dust  is  considered  Itas  than  that  made  by 
the  vertical  saw  or  the  lar^e  circular  saw.  The  latter  machine  is 
very  difficult  to  operate  in  order  to  obtain  true  cutting  for  board 
work,  and  is  very  rarely  seen  in  the  boat  yards. 


THE  EQUIPMJiNT  OF  A  BOAT  YARD  107 

Anotlier  advantage  which  the  liorizontttl^band  saw  poasesses 
ovm'  the  vertical  frame  saw  is  that  the  deep  pit  associated  with 
tlie  lattei  machine  is  not  necessary  with  the  former,  because  it  i? 
fitted  above  the  floor  level ;  all  the  operations  connected  with 
the  working  of  the  machinery  can  be  supervised  by  one  man. 

Boatbuilders  who  have  the  horizontal  band  saw  installed  in 
their  yai^,  state  that  for  the  amount  of  work  it  turns  out,  the 
power  consumed  is  comparatively  \eaa  than  with  other  types  of 
machinea. 

An  individual  instance  can  be  quoted  where  toak  logs  averafjtng 
22  in.  in  diameter  wore  cut  into  3750  super,  ft.  of  sawing  in 
31  hours,  which  k  at  the  rate  of  lOUO  super,  ft,  per  hour. 

Like  every  other  similar  class  of  machine  it  is  essential  that 
the  operator  should  thoroughly  understand  tho  capacity  and 
use  of  the  band  oiill. 

Due  attention  must  he  given  to  the  (juestion  of  keeping  the 
saws  in  proper  conditinu,  and  in  order  that  every  tooth  shall  be 
made  to  the  same  bevel  and  all  the  angles  of  the  teeth  precisely 
alike,  it  is  much  cheaper,  in  tlie  hmg  run,  to  have  a  separate 
compartment  in  the  main  machinery  shed  and  erect  a  saw  sharpen- 
ing machine,  which  requires  very  httle  mdividual  attention  and 
less  skill  to  operate  than  that  which  is  needed  to  sharpen  a  saw 
by  hand. 

Where  wide  baud  saws  are  used  it  is  necessary  to  have  a 
brazing  apparatus  for  repairs. 

It  is  an  advantage  to  have  an  exhaust  pipe  arrangement  for 
clearing  tho  saw-dust  and  shavings  from  the  mill  finors  and  led 
to  a  separate  fireproof  ahed. 

Planing  Machines  should  ho  of  the  three-knife  cutter  type; 
they  are  often  nnuh  abused  and  their  cKciency  considerably 
reduced  in  the  eft'urt  to  plane  every  type  oE  wood  in  the  same 
machine.  It  stands  t«  reason  where  cutters  have  been  iisod  for 
smoothing  down  teak,  oak  or  elm,  that  poor  resulta  will  be 
obtained  on  the  surface  of  yellow  pme  or  larch  planks.  Fur  this 
reason  a  number  of  builders  have  two  machines  in  their  shed, 
and  the  results  are  worth  the  additional  outlay. 

A  good  Band  Saw  is  an  indispensable  accessory  in  the  machine 
shed  and  for  the  purpose  of  cutting  heavy  crool^  for  deadwoods, 
etc.,  it  should  be  fitted  with  a  canting  table. 

A  Swing  Cut-oR^  Sawing  Machine  is  a  handy  little  machine  for 
cutting  oH  butt  ends  of  timber,  oto.,  but  it  should  be  carefully 
used. 

A  large  and  small  Circular  Saw  are  essential  refjuirements, 


J 


108 


SHIPS'  BOATS 


fitted  with  saws  from  12  to  30  in.,  having  adjustable  iron  tables  ' 
and    adapted   for   ripping,    eroaa   cutting,    and   bevel    sawing. 
Provision  should  be  made  for  fitting  grooving  saws. 

The  Vertical  Spindle  is  a  machine  which  can  be  utiJised  for  a 
number  of  purposes.  It  requires  the  greatest  care  in  operating, 
and  there  are  very  few  men  who  are  skilled  in  its  uae.  Means 
for  protecting  the  machinist  should  always  be  provided.  A 
greater  return  for  the  original  outlay  is  obtained  from  this  machine 
than  any  other  in  the  boat  yaul,  if  a  skilled  operator  can  be 
obtained.  Two  spindles  are  more  satisfactory,  revolving  iu 
opposite  directions,  ao  as  to  operate  in  the  same  direction  as  the 
grain  of  the  wood. 

The  timbers  can  be  rounded  with  this  machine  very  ex- 
peditiously, and  the'bcarding  taken  oi!  the  stems  and  sternposte. 

The  shed  for  seasoning  timlKr  should  have  a  good  protective 
roof  with  sides  which  will  allow  a  free  passage  of  air.  It  is  a 
very  short-sighted  policy  for  any  boatbuiider  to  attempt  to 
construct  lifeboats  without  providing  facilities  for  properly 
seasoning  the  material.  To  allow  oak,  elm,  or  thin  scantling 
material  to  indiscriminately  lie  about  the  yard  exposed  to  the 
sun  and  rain,  is  to  court  disaster,  and  it  would  be  a  safe  statement 
to  make,  that  a  very  large  percentage  of  builders  do  not  exercise 
the  care  they  should  in  this  direction. 

Now  that  a  boatbuiider  can  anticipate  his  requirements, 
through  the  principle  of  standaidisation  of  scantlings  having 
been  recognised,  it  is  a  great  advantage  to  cut  all  the  material 
to  size  and  stow  it  away  in  a  separate  shed  ready  for  use.  Thia 
provision  particularly  applies  to  deadwoods,  stems,  etc. 

Veiy  little  foresight  is  exercised  by  the  majority  of  boat- 
builders  in  designing  the  building  shed  to  suit  their  requirements, 
especially  where  pontoon  boats  or  open  boats  of  (.'lass  Ha  are  to 
be  constructed.  A  considerable  waste  in  labour  and  money  is 
the  result  of  maidng  inadequate  prtjvision  for  suitable  mechanical 
power  to  lift  and  transport  the  boats  during  and  after  construction. 

The  operation  of  removing  a  boat  from  one  berth  to  another, 
or  transporting  it  to  a  lorry  or  railway  truck  entirely  by  manual 
labour,  should  be  discouraged,  as  the  method  is  antiquated  and 
co.tly. 

The  shed  should  therefore  be  designed  with  overhead  rails 

and  mechanical  appliances  that  can  be  easily  operated  by  two 

,  and  the  pontoon  boats  easily  turned  over  or  removed  to 

another  berth  without  interfering  witli  the  men  already  engaged 

on  the  construction  of  boats  situated  in  other  parts  uf  the  shed. 


THE  EQITPMENT  OF  A  BOAT  YARD 


109 


The  follnwinji  general  Bcheme  in  operation  in  one  of  the  boat 
yards  recently  erected  on  the  river  Clyde  is  to  be  commended : — 

A  central  overhead  rail  runs  throughout  the  length  of  the 
building  shed,  connecting  each  individual  berth.  Provision  is 
made  for  transporting  the  boats  through  the  sliding  doors 
immediately  opposite  the  berth  by  nmning  bogies  imder  the 
keel  and  transferring  them  through  an  open  passage  outside  the 
shed,  to  a  gantry  fitted  with  mechanical  means  for  lifting  the  boat 
on  to  the  railway  truck  or  lorry. 

Benches  should  be  fitted  in  each  building  berth  and  the 
latter  numbered.  Full  information  giving  sizes  and  particulate 
of  boat  must  be  placed  in  a  prambient  position,  so  that  individual 
mechanics  are  in  possession  of  aU  the  requirements.  Many 
unnecessary  mistakes  have  been  made  through  carelessness  on 
the  part  of  the  foreman  in  giving  verbal  instructions  to  the  men 
which  have  been  raiaunderstood.  All  the  particulars  relating  to 
scantlings  of  material  and  details  of  specification  should  not  only 
be  kept  in  the  office,  but  circidated  among  the  individuals  who 
have  to  construct  the  boat. 

It  is  also  a  good  scheme  to  arrange  the  berths  so  that  as  soon 
as  one  boat  has  been  so  far  completed  on  the  keel  board  as  to  be 
easily  removed,  it  can  be  finally  finished  off  in  the  adjacent 
berth.  This  methinl  of  procedure  enables  the  work  to  be  carried 
out  systematically  and  ensures  a  quicker  iintput.  The  machinery 
shed  is  kept  constantly  busy  and  the  steam  chest  is  practically 
in  full  operation  during  the  whole  process  (tf  construction. 

Very  few  boatbuildets  have  the  facilities  for  making  their 
own  lifting -hooks,  inm  knees,  and  other  forged  iron  work.  It  is 
the  general  practice  on  the  Clyde  bo  obtain  all  the  iron  fittings 
from  a  smith,  and  the  system  of  standardisation  of  details  ensures 
the  Wfirk  coniing  to*the*boatbuilder  with  the  least  amount  of 
trouble. 

TTie  manufacture  of  buoyancy  air-caaes  is  a  trade  which  can 
be  undertaken  to  the  best  advantage  by  a  tinsmith  or  sheet-iron 
worker,  and  'the  large^'percentage  of  boatbuitdera  will  find  it 
cheaper  and  more  satisfactory  to  deal  with  the  expert  who  Is 
able  to  gauge  the  correct  amount  of  metal  to  be  used  fur  the 
I  particular  size  of  boat  under  construction. 


SECTION  A.— CONSTRUCTION  OF  CLASS  Ia  OPEN 
LIFEBOATS 

ScantUngs.^Referc^Qce  has  already  been  made  tu  the  necosaity 
iif  a  reoofiiiised  scheme  of  scantlings,  whitih  should  become 
opprative  in  all  yards,  to  enable  the  boatbiiilders  to  select  the 
most  suitable  material  and  of  such  dimensions  as  will  be  sufficient 
to  meet  the  heavy  stfessea  which  come  upon  a  loaded  boat  when 
beinf5  launched  from  the  davits. 

The  detaiU  shown  in  Table  XIV.  are  being  worked  to  by  a 
large  number  of  the  boatbuilders ;  the  various  sizes  are  based 
on  the  length  of  the  boat.  If  reference  is  made  to  Table  VII.  it 
will  be  seen  that  there  is  very  little  variation  in  the  dimensions 
of  lifeboats,  and  particularly  those  which  have  beeen  suggested 
as  standard  sizes.  A  large  number  of  fii'ms  have  already  adopted 
the  principle  of  standardisation,  the  outcome  being  that  the 
work  in  the  yard  becomes  simplified. 

All  the  work  of  the  allied  trades  associated  with  boatbuilding 
is  made  much  easier  if  the  detail  fittings,  such  as  iron  thwart 
knees,  breaathooks,  etc.,  are  ordered  on  a  basis  of  length  of  boat. 

The  various  lengths  of  open  boats  of  Class  Ia  and  Ib  have 
been  gro\iped  together,  on  the  assumptirm  that  eac'h  particular 
length  of  boat  possesses  definite  proportions  in  its  dimensions  ; 
that  when  loaded  and  suspended  from  the  davits  certain  maximum 
stresses  are  encountered.  Each  particular  detail  of  construction 
has  therefore  been  designed  to  reduce  the  effect  of  these  stresses. 
and  to  maintain  at  the  same  time  a  reasonable  factor  of  safety. 

Lurid  at^coimts  of  disasters  at  sen,  when  launching  the  ship's 
lifeboats,  have  often  given  a  wrong  impression  of  the  actual 
facts,  but,  nevertheless,  it  is  very  essential  to  take  every  known 
means  of  combating  the  "unusual  circumstance,"  and  tu  provide 
life-saving  appliances  that  are  strong  enough  and  effective  for 
the  purpose  intended,  having  a  factor  of  safety  which  will  enable 
the  ship's  officers  to  maintain  complete  confidence  in  the  boato 
they  have  under  their  supervision. 


I 


21 

i 
Transoms  .     .     . 

1 

1 

1 

English  B 

1 

English  Elm 

-    -                             f- 

1" 

12" 

21 

RUDDKR       .      .      . 

22 

22 

Teak,  Elm       *" 
Plank  EancL 

10  ft. 

G  AU«  i  E  OF  Fasten- 
in*  IS    .... 

-> 

23 

Risings,  Solid  Gun^ 
Ends  and  Till 

Note. — All  Rooves  ti 

.-                 -        -                                             * 

Wrought  Iron  (2  i= 
Norway  Sj 

23 

24 

Ringbolts      .     .  . 

24 

25 

Li:N(jTir  OF  Mast  ' 

'  25 

Xoti\—\n  additi  onal  length  of  boat  not  catlings  of  a  higher 
c  are  rot i uired .  L  ^'^  /«<^"^'  P-  1 1 1  • 


grade  are  required 


1 


I 


CONSTRUCTION  OF  CLASS  Ia  OPEN    LIFEBOATS    111 

It  may  be  argued  that  a  better  p]an  would  be  to  baae  the 
acantlinga  on  the  number  of  persons  carried.  Owing  to  the 
small  variation  of  dtniensiona  associated  with  length,  it  practically 
amoimts  to  the  uame  thin^  ii  the  scanthngs  are  ba^ed  on  definite 
lengths  of  boat,  Thescbeme  shown  in  Tables  XIV. and  XVIII. 
has  been  in  operation  since  October,  1916,  in  the  largest  boat- 
building centre  in  the  British  Isles,  and  probably  the  largest  in 
the  world.  The  writer  baa  had  sufficient  experience  to  acluiow- 
ledge  the  simplicity  of  the  working;  of  the  scheme.  Take  one 
instance  alone :  when  it  becomes  necessary  to  order  the  iron 
knees  for  a  particular  boat,  all  the  boatbuilder  needs  to  quote, 
is  the  length  of  the  boat,  and  the  knees  are  delivered  to  him  from 
the  smith,  having  the  correct  depth  to  suit  the  position  of  the 
thwart  in  relation  to  the  gunwale,  and  the  holes  are  drilled 
to  allow  the  fastenings  to  centre  the  rubbers  and  gunwale,  as 
arranged  by  the  boatbuilder. 

The  Board  of  Trade  have  now  issued  detailed  instructions, 
making  the  latter  applicable  to  all  districta  in  the  United 
Kingdom,  and  the  information  in  this  text-hook  practically 
covere  all  their  requirements. 

Bevellinfi  the  fastenings  to  catch  the  combinations  or  knees 
liaving  their  throat  securities  attached  to  the  binding  atrake 
below  the  rubber,  at  the  ends  of  a  boat,  are  practices  which  can 
be  avoided,  if  a  standard  scheme  is  in  operation  between  the 
allied  trades. 

Liftiug-hooks  and  sail  areas  are  also  based  on  the  length  of 
boat. 

It  need  hardly  be  mentioned  that  a  common  minimum  scheme 
of  scantlings,  made  apphcable  to  aU  districts,  provides  a  fair 
basis  for  competition  among  boatbuilders,  and  ensures  a  satis- 
factory type  of  boat,  if  construction  is  carried  out  in  accordance 
with  the  specifications. 

A  fair  latitude  is  given  in  the  list  of  materials  to  enable  the 
various  firms,  in  widely  scattered  districts,  to  have  accees  to 
timbers  which  are  easily  procurable. 

It  ia  obvious  to  any  one  associated  with  the  indnstrj',  that 
no  matter  how  detailed  ai'.d  explicitly  arranged  a  scheme  of 
scantlings  may  be,  there  are  two  essentials  which  are  of  the 
greatest  importance,  and  must  be  carried  out  if  the  lifeboats  are 
to  serve  the  purpose  for  which  they  are  intended,  viz, — honest 
workmanship  and  the  use  of  smsotunl  material. 

Preliminary  Information. ^Before  construction  is  commenced 
on  any  ijoat  it  is  essential  for  the  boatbuilder  to  secure  all  the 


112  SHIPS'  BOATS 

nGc«sary  infomiatiou  from  the  shipbuilder  that  will  (enable  him  1 
to  proceed  with  the  work  without  interruption.  The  following  J 
details  should  be  given  by  the  shipbuilder  when  ordering  the  boats  | 
for  a  particular  ship,  viz.  :— 

(1)  The  class  of  boat  to  be  constructed. 

(2)  \\'hether  boat  forms  part  of  the  Statutory   Equipment   | 
of  fie  vessel. 

(3)  Whether  double  bowed  or  square  stem. 

(4)  Whether  vessel  is  engaged  in  the  Foreign  or  Home  Trade:. 
(6)  Dimensions  of  boat  (L  X  B  X  D), 

(6)  Material  of  planking. 

(7)  Whether  full  equipment  ia  required  to  be  suppUed. 
-  (S)  The  position  of  the  liftini; -hooks  in  relation  to  the  fore   , 

edge  of  rabbet  at  stem  and  after  edge  of  rabbet  at  stempost,  oi 
their  relation  to  the  extreme  ends  of  the  boat ;  in  any  case,  it 
should  be  definitely  stated  wliere  the  positions  of  the  hooks  are 
to  be  taken  from.  To  avoid  any  discrepancy  the  distance 
between  the  hooks  should  also  be  given. 

(9)  The  type  of  davit  under  which  the  boats  will  be  suspended 
or  stowed. 

(10)  Any  additional  fitting  required  by  the  shipbuilders  which 
is  not  mentioned  in  the  Rules  for  Life-saving  Appliances. 

Having  this  detailed  information,  the  boatbuilder  can  proceed 
on  the  construction  without  interruption,  provided  he  has  arranged 
for  a  continuous  supply  of  material,  and  given  out  in  good  time 
the  sub-contracts  for  delivery  of  iron  work,  equipment,  etc, 

Large  firms  usually  stock  a  quantity  of  thwart  knees,  breast- 
hooks,  etc.,  and  prepare  themselves  to  meet  every  emergency  by 
anticipating  the  requiremeuti}  of  the  shipbuilder. 

A  great  deal  of  work  has  often  been  unnecessarily  scrapped 
when  the  boats  have  heen  nearing  completion,  througli  lack  of 
thought  on  the  part  of  the  boatbuilder  t«i  secure  this  preliminary 
information  from  the  shipbuilder,  before  laying  down  the  keel 
of  the  boat. 

Keel. — The  foundation,  or  what  is  generally  referred  to  aa  the 
"  keel  board,"  should  be  made  from  sound  and  substantial 
material,  from  111  to  12  in.  in  depth  and  from  4  to  5  in.  in 
thickness. 

Thekeel  board  is  tied  to  good  heavy  foundation  blocks,  anchored 
in  the  groimd  and  prevented  from  movement  by  piles  or  stakes. 
The  ground  should  be  of  solid  formation  and  the  blocks  arranged 
at  short  intervals  under  the  keel  board,  to  prevent  hogging  or 
In  this  respect  some  firms  give  the  keel  board  a 


CONSTRUCTION  ^F  CLASS   Ia  OPEN  LIFEBOATS    113 

slight  camber  to  make  up  for  the  weight  of  the  boat  acting  on 
the  keel  between  the  points  of  support,  when  stowed  in  position 
on  the  Vessel,  as  the  tendency  at  one  time  was  for  a  sagging  stress 
to  be  exerted  on  the  keel.  Now  that  the  stowage  chocks  must 
be  fitted  at  the  quarter-length  of  boat  from  stem  and  stempost, 


MOG  ptecc 


\  MOO  ^p/£ce\ 


(8€EL£D) 


B 


aoARo 


f 


FOUNDATtOrf  SIOC^ 


I 
I 

r ' 

I 


f^ 


ff/rOO^O  LB¥£L 


Fio.  30. 

A.  arrnngeiiioiit  of  keel  boanis  and  fouudatluiw. 
K,  method  uf  hei'uriiiR  hoR-]dece  to  keel  and  garboardH. 
(/.  iiietho<l  of  w>curinK  timbers  to  hotf- piece  and  sarboardn. 
D.  uection  of  keel  board  arrangement. 


there  appears  to  be  no  necessity  to  arrange  for  any  camber  on 
the  keel  board. 

The  general  arrangement  of  keel  board  and  foundation  is 
shown  in  Fig.  30  a  and  d. 

There  is  a  limiting  depth  between  the  top  of  the  keel  board  and 

1 


114  SHIPS'  BOATS 

the  ground,  which  should  not  be  less  than  15  in.  This  distance 
allows  suflicient  space  for  the  free  use  of  the  hammer  when 
clencliing  up  the  plank  fastenings,  but  more  particularly  when 
driving  in  the  timber  nails  from  the  garboard  strake  to  tie  turn 
of  the  bilge. 

Incidentally,  it  provides  a  good  opportunity  for  an  inspector 
of  ordinary  proportions  to  watch  the  quality  of  the  planking  as 
progress  is  made  with  the  construction. 

The  keel  must  be  in  one  length  and  selected  from  material 
which  is  straight  in  the  grain,  all  objectionable  knots  and  swirls 
being  carefully  avoided.  The  scantlings  vary  from  6^  moulded  X  3^ 
sided,  for  a  30-ft.  boat,  to  4''x2J"  for  a  16-ft.  boat. 

The  most  suitable  material  for  keels  is  American  rock  elm, 
which  is  of  fine,  close,  and  even  texture,  free  from  knots  and  gives 
c<msiderable  kmgitudinal  strength.  Next  in  order  of  suitability 
is  oak,  which  must  be  straight-grained  and  free  from  knots  ; 
otherwise,  unless  the  material  is  thoroughly  seasoned,  it  opens 
out  in  way  of  the  knots,  paiticularly  if  the  lower  portion  of  the 
keel  has  cut  through  a  knot  running  in  a'vertical  direction. 

English  and  wych  elm  have  been  used  for  keels  as  substitutes, 
during  the  period  of  the  war,  by  increasing  the  scantlings,  but, 
generally  speaking,  they  should  be  dropped  in  preference  to 
ro(;k  elm  and  oak.  Grey  elm  should  be  avoided  on  every  occa- 
sion ;  it  is  nothing  more  than  swamp  wood  and  lacks  strength, 
llexibility,  and  resihence. 

'J'h«  keel  is  placed  on  the  keel  board  and  kept  perfectly 
straight  in  a  fore  and  aft  dire<!ti()n  by  driving  in  wedges  between 
the  k<;el  and  cleats  attached  to  the  keel  board,  as  shown  in  section 
at  Fig.  30  J). 

The  top  edges  of  the  keel  arc  champhered  to  enable  the 
garboard  strake  to  have  a  square  landing  edge,  which  should  be 
carefully  performed  to  provide  a  satisfactory  scum  for  caulking. 

Stem  and  Sternpost. — The  combination  between  the  stem, 
st'Crnpost.  and  keel,  nmst  be  of  an  efficient  character,  and  the 
material  employed  of  the  best  (luality.  The  stem  and  sternpost 
is  usually  of  oak  and  select^'d  from  well-seasoned  timber  grown 
to  shape.  The  necessity  for  good  crooks  to  be  litted  at  the 
combinations  is  obvious  to  the  practical  man,  but  during  pre-war 
days  there  was  always  a  very  great  difficulty  to  satisfy  the 
requirements  of  the  boatbuilder  in  this  respect.  The  opening 
up  of  the  market  for  home-grown  timber  in  recent  yeiirs,  has 
created  a  better  supply  of  crooks,  and  this  supply  has  always 
met  the  demand  if  sufficient  trouble  was  taken  to  inform  the 


r 


CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS    115 

timber  merchant  of  actual  requirements.  The  usual  procedure 
has  been  to  blow  up  the  roots  of  trees  by  dynamite  instead  of 
lifting  them  by  the  more  tedious  process  of  digging ;  so  that 
the  majority  of  crooks  were  obtained  from  branch  wood.  The 
necessities  of  the  boatbuilders  having  become  known,  timber 
fellers  are  now  able  to  give  a  better  selection  of  material. 

In  the  first  place,  standard  moulds  should  be  kept  by  the 
boatbuilder  to  enable  him  to  apply  the  same  to  the  timber  before 
conversion  and  secure  the  beat  advantage  in  regard  to  grain. 

A  pleasing  shape  to  the  stem  makes  all  the  difference  to  the 
appearance  of  a  boat.  A  sharp,  stumpy  stem  worked  in  to 
avoid  a  long  crook  does  uot  allow  the  planks  below  the  bilge  to 


I 


Fio.  31. — VertiuBl  sCBq>b  of  sl«m  to  kwl. 


be  Unished  off  at  the  hood-ends  in  graceful  curves  and  in  con- 
lonnity  with  the  lines  of  the  boat.  It  is  somewhat  difficult  to 
explain  how  this  occurs,  but  the  difference  between  the  two 
types  of  stems  and  their  effect  on  the  planking,  is  very  apparent 
in  the  boat  yard.  The  grain  of  the  wood  at  the  heel  of  the 
stem,  where  it  scarplm  with  the  keel,  should  run  in  the  same 
direction  as  the  grain  of  the  keel. 

I  The  eomiection  between  the  keel  and  the  stem  and  stern- 
|>ost,  so  fur  as  ships'  boats  are  concerned,  is  efficiently  made  by  a 
vertical  or  a  horizontal  sL^arph.  The  vertiail  scarpk  is  the  more 
popular  one.  and  is  shown  in  Fig.  31.  The  method  provides  a 
better  opportunity  to  secure  a  suitable  crook  and  lends  itself  to 
simpler  attachment  than  the  horizontal  scarpb.     The  vertical 


11(> 


SHIPS'  BOATS 


scarph  practically  means  a  "'  half-check ''  and  the  keel  and 
Htoni  are  well  secured  by  at  least  five  through  fastenings ;  these 
should  be  of  substantial  gauge,  not  the  usual  timber  nail  and 
clenched  over  roovos,  but  copper  rod  of  4  or  5  S.W.G.  and 
clenched  over  washers  ;  rooves  are  far  too  thin  for  this  purpose. 

As  shown  in  Fig.  31  many  firms  snape  away  the  fore  upper 
edge  of  keel  and  make  the  stem  to  suit ;  such  an  arrangement  is 
considered  to  be  a  stronger  connection. 

The  horizontal  scarph  is  illustrated  in  Fig.  32,  the  length 
of  which  must  be  arranged  to  take  three  fastenings.  The  heel  of 
the  stem  nuist  of  necessity  be  a  perfect  crook,  otherwise  the 
connection  is  of  little  use.     The  centre  of  the  three  fastenings  in 


•i 


Fui.  32.—  HfH-izdiitil  rtCiirpli  of  sti'm  to  kcil. 

the  scarph  is  usually  left  until  the  doadwood  is  worked,  when  a 
l(mg  bolt  is  arranged  lo  catdi  the  keel,  stem,  and  deadwood. 

Whether  the  stem  is  secured  to  the  keel  with  a  vertical  or  a 
liorizcmtal  scarph,  the  full  thickness  of  the  keel  must  be  preserved 
right  out  to  the  face  of  the  stem,  and  the  bearding  arranged  to 
commence  from  about  four  inches  above  the  top  of  the  keel  with 
an  easy  curve.  The  bearding  is  about  one  and  a  half  inches  in 
breadth  on  the  face  of  the  stem  in  30-ft.  open  boats  and  about 
one  inch  in  small  boats.  A  strong  stem  can  be  made  by 
preserving  the  thickness  of  the  back  out  to  the  face,  for  a  dei)th 
of  about  14  in.  from  the  stem  head,  and  running  into  the 
bearding  in  a  similar  fashion  to  that  arranged  at  the  heel. 

The  sizes  of  the  head  and  heel  of  stem  and  sternpost  are 
shown  in  the  scantling  Table  XIV. 

Care  should  be  exercised  in  fitting  the  scarph  so  that  the 
stem  and  sternpost  plumb  the  centre  line. 


CONSTRUCTION   OF  CLASS  Ia  OPEN  LIFEBOATS    117 

There  is  very  little  difficulty  to  eecure  suitable  mat-erial  for 
the  stempost,  unless  the  boat  is  of  the  double-bowed  type.  The 
necessity  for  a  crook  does  not  arise  aud  the  usual  vertical  scarpli 
is  worked  as  a  connection  to  tlie  keel  and  secured  in  a  similar 
manner  to  the  stem.     (See  Fijr.  37.) 

When  the  connections  have  been  completed  and  fastenings 
properly  clenched,  the  stem  and  stempost  ace  mitde  to  plumb, 
and  their  heads  are  .secured  by  shores  to  some  pei'munent  part  of 
the  boat  shed. 

Reference  is  made  to  the  Htem  and  stempost  rabbets  when 
discussing  the  question  of  planking. 

There  have  been  alternative  methods  of  connecting  the  stem 
to  the  keel,  worked  at  one  time  or  another  in  the  various  boat 
yards.  Tlie  method  shown  at  Fig.  3,1  is  a  Hlight  modification  to 
the  vertical  searph  as  illustrated  in  Fig,  31.  It  will  be  noticed 
that  a  check  is  taken  out  of  the  deadwoiMj,  which  provides 
additional  strength  to  the  securities  of  the  stem  scarph.  The  con- 
nection shown  at  Fig.  34  ie  not  recommended,  although  it  is  very 
simple  and  entails  the  minimum  amount  of  labour.  A  few 
years  ago  the  majority  of  the  yards  went  so  far  as  to  simply  step 
tlie  stem  on  tlie  keel,  without  even  making  a  chock  in  the  latter, 
relyuig  on  the  throat  bolt  for  the  main  security  of  the  comiection. 

Fig.  35  is  an  illustration  of  a  practice  sometiuies  seen  in  the 
construction  of  motor  boats,  where  tlie  deadwood  is  made  to 
dovetail  between  the  stem  and  keel.  The  stem  and  apron  are 
in  one  piece,  the  rabbet  for  the  hood-ends  of  planking  being  cut 
as  indicated  in  the  figure.  It  is  very  essential  that  the  deadwood 
should  be  of  selected  material  and  very  carefully  cut  and  fitted. 
The  efficiency  of  the  conneirtion  greatly  depends  on  the  securities 
and  the  quality  of  the  workmanship.  The  writer  has  a  personal 
antipathy  to  any  form  of  combination  which  does  not  jirovide 
a  gcHid  faying  surface  for  the  reception  of  the  planking,  and  the 
practice  referred  to  is  an  instance  of  the  difficulty. 

Fig.  36  is  a  further  illustration  of  the  keel  and  stem  comiection, 
and  is  made  with  a  dovetail  check  taken  out  of  the  keel,  having 
a  throat  bolt  security  to  the  deadwood,  just  clear  of  the  check. 
This  arrangement  ia  quite  a  common  practice.  A  superior 
method  is  that  of  increasing  the  thickness  of  the  stem  at  the  heel, 
BO  as  to  combine  the  dovetail  check  and  the  horizontal  scarph 
and  make  provision  for  three  through  fastenings.  It  is  very 
essential  to  secure  material  which  has  been  cut  from  timber 
grown  to  proper  shape,  otherwise  the  connection  is  useless  after 
tie  boats  have  been  in  service  tor  twelve  months.     The  lifeboats 


i 


118 


SHIPS'  BOATS 


constructed  for  vessels  owned  by  Mesais  Alfred  Holt  &  Co.,  of 
Liverpool,  have  their  stem  and  stempost  connections  made  in 


Fia.  33. 


Fro.  34. 


accordance  with  the  metliod  described,  and  tliis  is  sufficient 
evidence  of  its  v^alue. 

The  stem  and  sternpost  heads  are  kept  down  as  low  as  possible 
so  that  they  do  not  project  above  the  gunwale  as  to  be  a 
source  of  danger.  They  are  so  shaped  as  to  easily  clear  ropes  and 
wreckage.  Some  firms  cut  the  stem  and  stempost  heads  and 
tlie  aprons  flush  with  the  gunwale,  others  allow  a  slight  projection 


ro^£  £0€i 


Ci   'ff^t 


J" 


4PftOf^ 


H-^ f-.--'   ^ 


6 


7> 


fy/'f  I 


'     ffECL 


oovcrA/t 

CHrCM 


^ 


Fio.  35.  Fifi.  3ri. 

Altorn.'itivr  methods  of  lltting  .sU*m  to  keel. 

above  the  stem  and  Htcrnpost  knees,  but  well  rounded,  so  as  to 
preserve  a  finishoil  apj)earance. 

The  bearding  of  the  stem  can  be  done  with  the  aid  of  the 


CONSTRUCTION  OF  CLASS  Ia   OPEN  LIFEBOATS    119 

spindle,  but  the  operation  is  a  tricky  one  and  needs  the  skill  of  an 
experienced  machinist.  The  use  of  the  machine  referred  to  saves 
much  labour,  gets  through  the  work  speedily,  and  gives  a  finished 
appearance.  The  stem  is  shaped  at  the  band  saw  and  can  be 
practically  prepared  ready  for  dressing,  and  it  is  in  such  detail 
work  that  the  value  of  a  good  man  supervising  the  machinery 
comes  into  operation.  Many  firms  still  rely  on  the  unnecessary 
use  of  the  adze ;    this  tool  could  at  least  be  much  restricted  if 


• 


t    -V.  : 


^ceL 


SM£C  SA/VO 


Fi(!.  37.   -Vertical  soarpli  of  sternpost  to  ko«*I. 


the  men  had  the  opportunity  of  being  trained  in  the  manipulation 
of  the  many  labour-saving  devices. 

The  rake  of  the  sternpost  is  from  4  to  G  in.,  so  as  to  pennit  of 
the  full  floor  being  worked  well  aft. 

Hog-Piece. — To  provide  a  good  landing  edge  for  the  garboard 
strake  and  a  solid  connection  for  the  timbers,  a  hog-piece  is  worked 
in  one  length  on  top  of  the  keel  and  checked  under  the  deadwoods. 
The  material  is  usually  American  rock  elm  and  should  be  of 
straight  grain,  free  from  shakes,  and  not  less  than  1  in.  in 
thickne^ss,  to  ensure  a  solid  foundation  for  the  caulking  seam. 
The  h(;g-piece  is  secured  to  the  keel  by  stout  screws,  about 
2|  in.  in  length  and  G  in.  apart,  worked  in  reel  fashion  as 
shown  in  Fig.  30  ii.  These  screws,  therefore,  come  midway  between 
the  timbers  and  are  arranged  after  tlie  positions  of  the  latter  are 
indicated  on  the  upper  surface  of  the  hog-piece. 

The  width  of  the  hog-piece  is  given  for  every  length  of  boat 
in  Table  XIV.  and  is  arranged  in  each  case  to  provide  a  good 
bearing  for  the  garl>oard  plank  landings  and  the  timber  fastenings. 


120  SfflPS'  BOATS 

Defectively  caulked  seamB  at  the  sand  strakes,  or,  what  is 
usually  termed  south  of  the  border,  the  garboard  strakes,  are 
often  caused  through  the  timber  nails  being  "  dump  "  instead 
of  ''through"  fastenings,  and  clenched  over  rooves  as  shown  in 
Fig.  3()  c.  The  operation  of  clenching  the  timber  fastenings 
through  the  hog-piece  should  be  undertaken  at  the  first  oppor- 
tunity and  before  the  keelson  is  fitted  in  position. 

The  spacing  of  the  timbers  governs  the  pitch  between  the 
keelson  fastenings  and  is  therefore  a  multiple  of  G  in.,  and 
usually  not  more  than  24  in.  The  whole  of  the  fastenings,  in  con- 
junction with  the  position  of  the  timbers,  are  marked  in  position 
on  the  liog-pieoe,  immediatdy  the  latter  is  temporarily  secured 
in  positi<m  on  the  keel. 

Deadwoods.  —  Keference  has  already  been  made  to  the 
necessity  of  strong  and  efficient  combinations,  and  more  attention 
has  recently  been  given  to  the  quality,  form,  and  scantlings  of 
the  deadwoods.  The  im{)ortanGe  of  having  good  material  free 
from  cross  grain,  and  selected  from  timber  grown  to  shape,  is 
obvious.  The  deadwoods  form  a  solid  stmt  to  the  stem, 
sternpost,  and  keel,  distributing  the  stresses  to  the  frame  of 
boat,  which  arc  received  through  the  lifting-liooks.  The  form  of 
the  dcadwood  should  be  such  as  to  receive  the  maximum  amount 
of  support  from  the  timbers,  planking,  and  combinations,  and 
for  this  reason  it  sliould  be  sided  so  as  to  preserve  a  fttU  faying 
surface  for  the  reception  of  the  planking.  This  provision  also 
possesses  tlie  added  advantage  of  preventing  the  accuumlation 
of  water  and  dirt  between  the  planks  and  deadwood,  which  is 
an  important  matter  in  view  of  the  position  of  the  deadwood 
being  at  the  ends  of  the  boat,  covered  in,  and  very  rarely  inspected. 
This  precaution  is  somewhat  difficult  to  carry  int^)  effect  with 
the  largest  ty[)e  of  lifeboats,  as  it  requires  a  very  big  crook  to 
obtain  the  fall  faying  surface  from  plank  to  plank  at  the  midship 
end  of  the  deadwood. 

Provideti  a  faying  surface  of  3  to  3J  in.  is  preserved  for 
the  double  fastenings  at  the  hood-ends  or  plank  landings,  it  is 
admissible  to  fill  in  the  intervening  space  between  the  deadwood 
and  planks  with  filling  pieces,  efficiently  secured  to  the  deadwood 
before  the  planking  is  worked.  These  filling  piece^s  should  be 
well  bedded  in  thick  white-lead  oil-paint  and  arranged  as  shown 
in  Fig.  39. 

It  has  rtxently  been  approved  for  the  throat  of  the  deadwood 
to  1)0  not  kvss  than  the  depth  of  the  keel  plus  1  in.,  the  siding  to 
be  sufficient  to  give  a  faying  surface  of  3  in.,  exclusive  of  the  rabbet. 


CONSTBUCTrON  OF  CLASS  Ia   OPEN  LIFEBOATS 

Deadwuods  cut  from  material  {ijrown  to  shape  are  more  easily 

procured  for  the  stem  than  for  the  aterapost,  owinj;  to  the  sharp 

angle  between  the  steriapost 

and    the    keel    being    about 

100". 

It  is  usually  impossible  to 

secure  more  Ihan  two  timbers 

across    the    <lea(l woods,    the 

heels  of  the  reuiaiuinn  timbers 

at  the  ends,  forward  or  ftft,  as 

the  case  may  be.  being  checked 

into  the  deadwooda,  which  re- 
lieves the  plank  fastenin<;s  of 

some  of  the  stresses  at  this 

position. 

Wliere  difficulty  occurs  in 

securing  suitable   dcadwoods 

which    would   provide  a  full 

fayint;  surface  from  plank  to 

plank  as  rihown  in  Fig.  40,  a 

practice  has  been  in  operation 

in  some  yards   to   fit  a  sole 

pi&K  on  tlip  keel  and  under 

the  deadwood.     The  straifilit 

grain  of  the  sole  piece  allows 

the  full  bearing  of  its  thick- 
ness  for  atta<;liment  to   the 

planks   and  can   be  brought 

sufficiently  towards  amidships 

to  become  incorporated  with 

the  keel  plates  of  the  lifting- 
hooks,  and  thus  take  ite  full 

share  of   the   stresses   which 

come  upon   the  boat  at  this 

particular  position.     Such  an 

arrangement  i.t  shown  in  ele- 
vation   at    Fig.   41   and   the  i'lti,  40, 

"  bnilt  up  "  deadwood  is  quite 
'  a  common  practice  for  fishing  vessels  constructed  on  the  west 
I  coast  of  Scotland. 

The  faying  surfaces  of  all  the  combination.^  should  have  a 
I  good  soaking  coat  of  white  lead  paint,  before  being  secured  in 

position. 


122 


SHIPS'  BOATS 


It  is  usual  to  arrange  for  five  through  fastenings  in  each 
deadwood,  the  upper  one  forming  the  scarph  connection  to  the 
apron,    ^\llen  boats  are  lifted  at  the  extreme  ends,  as  in  the 


»ff£lZOS 


^i^ao 


Fii:.  41.-- Huih-up  deadwood. 


"  Welin  "  type  of  davit,  it  is  necessary  to  pitch  the  fastenings  to 
enable  them  to  be  iiicorporateil  with  the  keel  plate  of  the  lifting- 
hooks.  Moulds  are  made  from  the  curvature  of  the  deadwood 
and  given  to  tlie  smith  f<»r  application  on  the  back  of  the  keel 


•'  / 


/ 

7' 


Qrr~-: ' 


/ 


He-^L. 


y 


y 


Fh;.  42.-  -Pfwitioii  of  i?topwat<*rs. 

I»lal<s  U)  ensure  a  close  lit  between  steel  and  wood,  thus  giving 
ellic.icnt/  b(*aring  for  securitie^i. 

The  connection  between  deadwoods,  keel,  stem,  or  sternpost, 


I 


CONSTRUCTION  OF  CF^ASS  Ia  OPEN  LIFEBOATS    123 

can  be  made  bj  |  in.  to  i'',-  in.  galvaniaed  iron  rod,  and  clenched 
over  washers,  or  preferably,  by  the  use  of  galvanised  screw 
bolts,  having  their  points  clenched  over  the  heads  of  nuts. 

The  latter  method  allows  a  final  adjustment  to  be  made  to 
the  fasteninga  before  clenching,  and  greater  power  is  provided 
for  drawing  the  faying  surfaces  together. 

To  prevent  leakage  at  the  connections  of  combinations, 
itopwaUrs,  made  of  anft  wood,  usually  yellow  pine,  are  inserted 
in  the  poaitionB  shown  in  Fig.  42  and  marked  A  and  B. 
These  Btopwatera  prevent  the  passage  of  water  into  the  boat  as 
a  result  of  leakage  through  the  scarphs  or  keel  seam  at  the  dead- 
wood  ;  a  provision  which  is  often  overlooked  in  the  rush  to 
complete  the  planking. 

Apron.— The  apron  is  that  portion  of  tlie  frame  combination 
which  is  attached  to  the  stem  or  stempost  and  pi'ovides  the 
surface  for  securing  the  hood-ends  of  the  planking.  Very  little 
difficulty  is  experienced  in  securing  suitable  material  as  tliere  is 
practically  no  curvature  in  its  form. 

Oak  or  elm  is  usually  employed  and  caie  must  be  exercised 
in  cutting  the  apron  to  shape,  to  preserve  sufficient  material  for 
fitting  the  hood-ends  of  the  planks. 

We  find  here  another  argument  fur  the  use  of  standard 
moulds.  Careleasness  in  trimming  or  cutting  the  faying  surfaces 
for  the  reception  of  the  planking  ia  often  responsible  for  tlie 
objectionable  practice  of  fitting  sliver  jneces  between  the  planks 

■  and  the  apron  t^  make  up  for  the  deficiency  of  material  in  tlte 
latter.  The  siding  of  the  apron  should  be  so  arranged  as  to  pro- 
vide a  fayui^'  surface  of  3  to  4  in.  for  the  hood-ends  of  planks,  so 
that  with  this  faying  surface  and  the  rabbet  cut  out  of  the  stem, 
there  ia  ample  material  for  the  reception  of  a  double  row  of  fasten- 
inga. Attention  should  therefore  be  given  to  see  that  the  apron 
I  is  trimmed  so  as  to  be  in  alignment  with  the  form  of  the  boat. 
The  securities  of  the  apron  to  the  stem  and  stempost  are 
similar  tti  those  which  pass  through  the  deadwood.  The  upper 
bolt  is  l]ttie<i  through  the  stem,  apron,  and  gunwale  breaat-hook ; 
the  second  is  the  ring  bolt  to  which  the  painter  is  attached ; 
obeerving  that  a  ring  bolt  should  be  fitted  at  both  ends  of  the 
boat  and  be  of  substantial  scantling  (see  Table  XIV.) ;  the 
third  bolt  passes  through  apron  and  stem ;  but  the  fourth  one 
usually  picks  up  the  luwer  breaat-hook  in  boats  of  24  ft.  in  length 
and  upwards  ;  the  fifth  bolt  forms  the  security  between  Uie 
apron  and  dcadwoul  scarph  with  the  stem  or  stempost. 
A  full  detail  of  the  formation,  connections  and  securities  of 


I 


J 


126 


SHIPS'   BOATS 


Fig.  45  was  taken  iiom  a  phatograph  of  a  boat  in  course  c 
construction  at  the  boat  yard  of  Messrs  Eobert  Eodfi;er  &  Co., 
Greenoi'k.  It  sLowa  clearly  how  the  apron  and  deadwooda  ' 
closely  fay  against  the  planks,  givinj^  very  little  opportunity  for 
water  or  filth  to  lie  between  tJie  surfaces,  and  in  this  case,  where 
the  timbers  cannot  cross  the  centre  of  the  boat  at  the  ends,  they 
are  checked  into  the  deadwood. 

Incidentally,  this  plate  also  shows  a  doubling  fitted  behind  a  i 
knot  in  a  larch  plank,  gripping  two  timbers  and  properly  secured  j 
with  copper  nails  clenched  over  rooves. 

In  districts  where  suitable  crooks  are  easily  procured,  it  is  J 
not  an  uncommon  practice  in  building  fishing  boats  and  motor 
craft,  to  have  the  apron,  stem,  and  deadwood,  in  one  piece, 
instead  of  being  separately  connected  together.     The  writer  has 
seen  some  very  fine  jobs  completed  in  yards  situated  on  the  I 
lower  reaches  of  the  Clyde,  with  solid  end  combinations,  but  J 
the  scheme  also  has  its  disadvantages,  particularly  when  any  J 
portitm  of  the  combination  needs  repairing  or  renewing. 

Keelson, — When  the  combinations  have  been  fitted,  securiKl, 
and  the  framo  of  the  boat  made  to  outwind  and  pluuib  the  centre  1 
ti.f-e-ico.f/tu  \ia.ii,  they  are  secured  I 

in  position  at  the  keel  J 
board    and    to    some  i 
permanent  part  of  the  I 
boat  yard.     The  posi- 
tions   of    the   timbera  j 
are  marked  on  the  hog- 
piece    and    the   hood-  1 
ends  of  planks  marked  I 
on  the  stem  and  stem 
post. 

Before  the  planking  J 

is    commenced    it    is, 

Fw  47.— Section  of  kwluiiUk.-pl«onrombiii<ilion.  "sual  for  the  keelBOft. 
to  be  cut  to  leug^. 
The  keelson  is  an  eesontial  part  of  the  structure  and  acts  aa  a 
very  substantial  support  for  the  heavy  load  of  a  fully  equipped 
boat.  It  is  arranged  with  the  section  as  shown  in  Fig.  47,  i.e. 
moulded  to  a  size  greater  than  its  sided  dimension ;  or,  in  other 
words,  its  depth  is  greater  than  the  width,  which  allows  for 
greater  strength  in  a  longitudinal  direction. 


The  keelson  should  extend  in 


B  far  forward  and  aft 


as  the  combinations  will  allow  and  become  incorporated  with  the 


CONSTRUCTION  OF  CLASS  Ia  OPEN   LIFEBOATS     127 

faatemngs  of  the  deadwoyds  and  keel.  The  keekon  should  be 
BO  worked  aa  to  take  the  whole  of  the  fastenings  of  the  lifting- 
hook  heel  plates  slb  illustrated  in  Figs.  43  and  44  which  gives 
additional  support  Ui  tlie  boat. 

At  this  period  of  the  construction  it  ia  only  necessary  to  cut 
the  keelson  to  length  and  fit  the  ends  to  the  form  of  the  dead  woods. 
It  ia  finally  placed  in  position  when  the  boat  has  been  planked 
and  timbered,  just  immediately  before  the  thwai-ts  arc  ioHerted. 
The  material  is  usually  of  pitoh  pine,  oak,  elm,  or  Oregon  pine. 
The  common  practice  among  boatbuilders  is  to  take  the  line 
of  least  reai.stance  and  fit  the  keelson  on  top  of  the  timbeis. 
This  method  allows  a  free  drainage  from  one  side  of  the  boat 
to  the  other. 

A  very  efficient  means  of  binding  the  backbone  of  the  boat 
and  giving  better  support  to  the  mast-step  is  to  check  the  keelson 
r  the  timbers  so  that  its  lower  surface  fays  with  the  upper 
surface  of  the  hog-piece,  the  depth  of  the  keelson  being  increased 
to  allow  for  the  checking. 

The  disadvantage  claimed  for  the  latter  method  is,  increase 
of  cost  due  to  extra  labour  required  in  fitting.  The  slotting  of 
the  keelson  for  the  timbers  must  be  very  carefully  done,  other- 
wise opportunity  is  given  for  water  and  dirt  to  find  their  way 
between  the  faying  surfaces  and  timbers,  which  encourages  wet  rot. 
It  ia  only  in  high-class  work  that  the  slotting  of  the  keelson  is 
undertaken,  and  therefore  more  care  has  to  be  exercised  in  the 
details  of  construction. 

The  two  methods  referred  to  are  illustrated  in  Figa.  48  and  53, 

The  keelson  is  well  secured  to  the  keel  and  deadwoods  by 

[  iiall-iuch    galvanised    iron    bolts    spaced    about    2    ft.    apart, 

"  either  clenched  over  washers,  or  secured  by  nuts  above  washers 

I  and  having  their  points  clenched  over  the  nuts.     To  give  a  solid 

I  bearing  in  way  of  these  securing  bolts,  solid  chocks  are  fitted 

I  between  the  two  timbers,  extending  the  full  width  of  the  keelson. 

In  the  case  of  some  types  of  motor  boats,  tu  provide  a  low 

I  seated  motor  it  is  not  always  practicable  to  fit  a  keelson,  and  in 

I   tiiese  cases  the  bilge  stringers  are  increased  in  scantlings  to  make 

up  for  the  loss  of  strength. 

Boats  carried  by  trawlers  are  not  usually  fitted  with  keelsons, 
I  as  they  would  interfere  with  the  particular  work  these  vessels 
I  »re  engaged  in. 

Transom,— In  completmg  the  description  of  the  construction  of 
[  the  framework  of  an  open  boat,  reference  b  made  to  the  methods 
\  of  fitting  the  transom  in  a  square-stem  boat.     Preferably,  the 


-HIPS"   BOATS 


rrATL^t  in  ?£i'-'i^«:  "•:•?  w- :ri.*c  in.  oe*  piece  and  sdectcd  from 
5»^;i>«  z-h:  EnJ^ii  -^iin-  riaiv^canj.  '"r  teak.    The  heel  of  the 


^SS"^  5*^  * 


\r 


r> 


-Cl 


HI. 


CJ. 


If  thero  :-  Ivika 


-   s^     -        -.•_-^—    •'      •-     » 


.r  i.  •» 


>:  ^t  aT^  Ar.jle.  as  shown  in  Ilg.  49 
i.i<  ni,  die  di£cultv  is  asualljr  to  be 


ripr 


UH 


V. 


-1  -i  -£ 


I 


.""5-  V 


^fc  -  • 


Fi-;.  4:'. 


K:   .  .--■. 


,1    »'J 


Fi«;;.  01.         Fig.  52. 


found  at  the  .seam  «.r  j.^int,  il  lit  tod  iii  balvf^.  or  at  the  heel.    To 
obviate  tliis  drawback,  the  wiiter  La^  ^ouiotimcj?  seen  a  dove- 


.Ci. 


*f££^5C'f 


.CALV     i^C^fAt. 


*«J^|J^'*^ 


THCiCM , 


I   • 
I   I 

I 


Fn;.  53. 


s jrt^^r  '"*"'""  ^''^  '^''^^  ^"'^  ^^«  «^-"p-t. 


r 
I 


CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS     129 

It  b  very  difficult,  at  times,  to  secure  sufficient  breadth  in 
tiie  material  to  allow  the  traiiaom  to  be  in  one  piece,  and  it  then 
becomes  necessary  t«  work  a  joint,  Fi^.  51  shows  a  method  of 
joining  the  two  pieces  of  transom  together  with  the  aid  of  a 
haH-check  and  secured  with  copper  fastenings  clenched  over 
rooves.  ,  This  makes  a  good  solid  job,  provided  the  securities 
are  closely  spaced,  and  should  any  shrinkage  take  place  in  the 
transom  the  joint  can  be  lightly  caulked  without  unduly  opening 
out  the  seam. 

Another  practice,  as  illustrated  in  Fig.  52,  is  to  fit  a  Je/Uher 
flip  between  tlie  two  pieces  of  transom,  but  this  method  does 


Pm.  54.- 


if-n  of  »lom|K)!l  iiend,  t 


«  nnd  trnnHom. 


not  give  the  solid  bearir^  for  a  light  caulk  as  the  one  previously 
referred  to. 

Where  fastenings  are  clenched  over  rooves  which  are  in 
contact  with  hard  wood,  such  as  oak,  it  is  usual  to  slightly  sink 
the  rooves  into  the  material. 

The  transom  is  also  secured  to  the  stempost  with  clenched 
fastenings  or  long  stout  screws. 

The  common  practice  is  to  cut  the  stempost  short  of  the 
cross-piece.  A  method,  which  it  is  considered  adds  strength  to 
the  combination  and  helps  to  prevent  the  transom  coming  away 
from  the  sternpost,  is  to  mortice  the  head  of  the  stempost  into 
the  cross-piece  as  shown  in  Fig.  54. 

The  Methods  of  fitting  fashion  pieces  to  take  the  hood-ends 
of  planks  and  sliver  pieces  at  the  heel  of  transom,  are  dealt  with 
Then  discussing  the  question  of  "  planking." 


RHTPS"  BOATS 

The  full  thickness  of  the  keel  is  carried  out  to  the  after  edge 
of  the  uterapoat  and  the  bearding;  is  coinmenced  a  few  inches 
above  the  keel,  so  as  to  take  the  rudder-braces,  as  shown  in 
Fig.  27. 

No  particular  rule  can  be  laid  down  as  to  the  width  of  the 
transoni,  which  if  generally  about  two-thirds  of  the  breadth  of 
the  boat. 

PlinUng. — Provided  the  scanthnga  of  the  combinations  are 
satiMfactory,  it  is  safe  to  state  that  the  most  important  operation 
in  connection  with  the  constraction  of  a  lifeboat  is  tho  planking. 
In  the  first  place,  to  secure  a  fair  fonned  boat,  with  eaey  curvature 
of  the  planks  and  satisfactory  soleing  for  the  landings,  it  is 
absolutely  essential  that  moulds  should  be  erected.  The  question 
of  a  suitable  form  and  the  various  salient  features  which  must  be 
observed  before  the  moulds  are  erected,  have  been  dealt  with  in 
some  detail  in  Part  II.,  Section  C. 

The  continual  alteration  of  dimensions  of  boats,  with  no  fixed 
minimum  dimensions  or  recognised  standards,  have  been  largely 
responsible  for  the  unsatisfactory  method  of  planking  a  boat 
"  to  the  eye."  It  stands  to  reason  that  the  boatbuilder  cannot 
possibly  stock  hia  yard  with  moulds  suitable  to  every  type  of  boat, 
hut  a»  standard  dimensions  are  gradually  becoming  the  rule  in 
most  districts,  there  is  every  incentive  givea  to  the  builder  to 
work  on  systematic  lines. 

From  tlie  writer's  experience  in  visiting  some  of  the  lai^est 
boatbuilding  yards  in  the  country,  unless  section  moulds  are  used 
in  every  case,  one  caimot  be  sure  of  two  boat«  being  alike.  The 
men  actually  constructing  the  boat  are  usually  dependent  on  the 
foreman  for  the  shape  of  the  plank  given  by  the  plank  mould, 
and  tlie  strakcs  are  worked  ami  fastened  according  as  it  suita  the 
tasto  of  the  individual.  When  the  planking  above  the  bilge  has 
BO  far  advanced  as  to  give  some  indication  of  the  breadth,  it  often 
happens,  in  the  absence  of  section  moulds,  that  the  form  has  to 
be  "  jiffled  "  to  suit,  a  practice  which  is  responsible  for  bad 
Boleing,  bringing  unnecessary  stress  on  the  plank  fastenings,  and 
eventually  results  in  split  planlcs. 

Three  section  moulds  are  considered  the  minimum  number — ■ 
one  at  amidships — and  one  at  the  quarter-Iejjgth  from  stem  and 
Bternpost. 

Some  firms  adopt  swing  moulds,  i.e.  half  sections  which  are 
pivoted  at  the  middle  line  and  can  be  swung  from  side  to  side. 
The  general  practice  is  to  work  to  fixed  moulds  which  are  not 
removed  until  the'operation  of  planking  is  complete. 


CONSTRUCTION  OF  CLASS  Ia  OPEN  IJFEB0AT8     131 

There  are  three  methods  of  planltinfj  lifeboats  ad'ipted  in 
Great  Britain:  the  "  muUiplc-skin''  (see  Figs.  71  and  72).  the 
"  carvel "  (see  Fig,  55),  and  the  "  clinker  "  (see  Figs.  67  and  87). 

No  doubt  exists  as  to  which  is  the  best  principle  of  construc- 
tion. The  multiple-skin  worked  diagonally  is  adopted  in  the 
highest  class  of  pulling  and  motor  boats.  This  method  provides 
an  exceptionally  strong  and  efficient  boat,  which  in  many  instances 
lasts  the  life  of  the  vessel.  It  naturally  follows  that  the  cost  of 
production  is  greater,  the  weight  is  increased,  and  there  is  greater 
difficulty  in  repairing  a  boat  when  damaged,  owing  to  the  insertion 
of  the  inner  skin  and  the  textile  material  between  the  two 
thicknesses ;  but  where  a  vessel  is  constantly  running  through  the 
tropics,  the  additional  initial  cost  to  the  shipowner  is  more  than 
repaid  after  a  few  years'  service. 

The  "  carvel "  method  of  planking  is  considered  to  be  next 
in  order  of  value  for  strength.  A  boat  built  on  this  principle 
has  flush  planking,  the  edges  of  which  are  fitted  close  together 
with  the  whole  inner  surface  having  continuous  support  from  the 
timbers.  A  carvel-built  boat  will  stand  more  knocking  about, 
with  less  chance  of  having  damaged  planks,  than  one  constructed 
on  the  "  clinker  "  system. 

A  "  single  "  skin  boat  should  be  built  with  just  as  much  care 
and  attention  as  is  given  to  the  "  niultiple-skin  "  boat.  The 
usual  experience  of  the  superintendent  or  the  inspector  is,  that 
the  simpler  the  method  of  construction,  the  less  precaution  is 
exercised  by  the  boatbuilder. 

The  "  clinker "  method  lends  iteelf  to  quick  procedure  in 
construction,  and  therefore  gives  early  delivery.  Eadi  plank 
runs  in  a  fore-and-aft  direction,  the  edges  are  lapped  or  landed 
one  im  the  other,  the  breadth  of  the  landings  is  usually  about 
J  in,,  the  limit  beiug  J  in.  Boats  thus  constructed  are  easily 
repaired  after  being  damaged,  and  with  simplicity  of  working, 
coupled  with  speedy  delivery  and  a  minimum  of  coat,  these  factors 
provide  the  main  reasons  why  the  majority  of  lifeboats  supplied 
to  merchant  vessels  are  built  on  the  "  chnker  "  method. 

The  ttuckuesB  of  the  planking  varies  in  accordance  with  the 
material  used.  Yellow  pine  and  larch  planks  are  J  in.  to  |i  in., 
while  wych  elm,  teak,  and  mahogany  are  worked  about  |',>  in. 
lees  in  thickness.  A  good  practice  existing  among  some  Arms, 
when  buildii^  yellow  pine  or  larch  boats,  is  to  work  in  the  two 
Btrakes  of  planking  adjacent  to  the  keel,  of  teak  wood. 

The  section  moulds  are  prepared  and  secured  in  position.  The 
position  of  the  planks  are  marked  on  the  midship  mould,  and  on 


^^        Tht 
^^1  positio: 


132  SHIPS'  BOATS 

the  stem  and  stempost  aft^r  the  standard  allowance  for  sheer 
has  been  t.aken  into  consideration.  The  usual  sheer  recognised 
in  the  boat  yards  is  |  in.  to  the  foot,  which  is  slightly  more  than 
4  per  cent,  of  the  length  of  the  boat,  the  regulation  standard. 

The  breadth  of  the  plnnk^  should  not  exceed  5J  in.,  with  the 
exception  of  the  ^arboard  and  its  adjacent  strake,  which  are 
permitted  to  exceed  this  limitm*^  breadth  up  to  7  in.  The 
landings  must  not  be  le^s  than  |  in.,  but  are  usually  ^  in.,  so  that 
the  width  of  plank  showinji  would  be  not  more  than  4|  in. 

Boats  of  21  ft.  in  length  and  downwards  usually  have  planks 
not  exceeding  5  in. 

In  order  to  j)reserve  a  uniform  appearance  to  tjie  planking,  the 
binding  strake  is  increased  in  breadth  by  the  thickness  of  the 
rubber,  so  that  the  actual  breadth  of  planking  showing,  is 
the  same  as  the  adjacent  strakes. 

The  particulars  given  in  Table  XV.  will  be  usefid  to  ascertain 
the  number  of  planks  required  in  various  boats  of  Classes  I  A,  Ib, 
and  III.,  which  are  built  on  the  **  clinker  "  principle.  If  these 
numbers  are  worked  to,  the  breadths  of  the  planks  will  be  within 
the  standard  Umits. 

TABLE   XV. 

Minimum  Number  of  Strakes  of  Plankino  in  (.^ltnkkr-built  Boats  of 

CiJ^ssES  I  A,  Ib,  and  111. 


Diiuensions  of  boats. 

Total  No.  of  strakes. 

300' X  1)0'  x:V7r>' 

17 

29-o'x«-7r/x:M)' 

17 

28-0' X  8-5'    xH-r/ 

10 

27  0' X  8-25' x:{-4' 

10 

2H0'>.80'   x:j-2iV 

15 

25o'x7-7r>'x:Mr)' 

If) 

24  0' X  7-5'    x:50' 

14 

230' X 7-5'    >  20' 

14 

22  0' x  7-25' X  2 -75' 

13 

210' X 70'   X2-7' 

13 

20-0' X  0-75' X  2-0' 

12 

19-0'x<i'5'   x2r)' 

12 

I80'x()-2r)'x2'4' 

11 

17O'x(>0'   X2-.S5' 

11 

IHO'X  5-75' x  2-3 

11 

Nothin<^  beats  hand-dressed  planks.  If  planks  are  passed 
through  the  planing  machine,  they  should  be  tou(h(»d  up  with 
the  hand-plane  before  being  worked  into  the  boat. 


CONSTRUCTION   OF  CLA(^S  Ia  OPEN  LIFEBOATS     133 

It  stands  to  reason,  if  the  blades  of  the  planing  machine  are 
used  for  oak,  teak,  elm,  and  other  hard  woods,  one  cannot  expect 
to  secure  a  proper  smooth  surface  on  the  larch  or  yellow  pine 
planks,  unless  a  planing  machine  ia  kept  expressly  for  the  purpose 
of  treating  the  soft  wooda. 

The  two  great  esaentials  for  securing  a  satisfactory  job  with 
the  planking,  ate  seasoned  niatertal  and  careful  attetUion  to  delaUs. 
In  the  first  place,  unless  the  timber  has  been  properly  treated  and 
pinned  at  least  twelve  months  before  being  required,  after  three 
months'  service  the  boats  will  become  lealtj'  and  of  little  use  as 
life-saving  appliances. 

Unseasoned  larch  is  easier  to  work  during  the  various  stages 
of  construction  than  the  bone-dry  material,  particularly  during 
the  operation  of  planking.  Seasoned  material  needs  greater 
care  when  drilling  for  the  faaterdnga  at  the  landings,  and  par- 
ticularly when  the  copper  nails  are  driven  through  the  timber. 
Roughly  treated,  the  material  splite.  Ail  the  defects  of  seasoned 
timber  are  seen  before  the  wood  is  painted.  The  difficulties 
with  unseasoned  planking  occur  aft«r  the  boat  is  used  in  service 
and  when  the  material  shrinks  after  exposure  t«  the  atmosphere. 
The  boat  cannot  hold  it^  form,  and  something  is  bound  to  go, 
consequently  the  planks  usually  split  along  the  landings  between 
the  fastenings. 

Dry  material  produces  a  hard  sound  when  touched  with  tlie 
hand  plane,  and  gives  a  glossy  surface  to  the  planks  when  finally 
dressed.  Unsi!asuned  material  always  remains  dull,  irrespective 
of  the  time  spent  on  the  dressing. 

Planks  should  not  be  kept  in  the  steum  diest  longer  than 
I'i  minutes,  otherwise  all  the  resinous  nature  of  the  material 
which  is  required  to  counteract  the  effect  of  the  weather  will  be 
driven  out.  If  the  material  is  unseasoned,  veiy  little  advantage  is 
to  be  obtained  by  keeping  the  planks  in  the  steam  chest  for  12 
hours. 

The  scheme  that  pays  the  boatbuilder  is  to  anticipate  his 
requirements  and  to  keep  sufficient  material  in  stock,  which  has 
been  well  pinned  down  under  cover  for  a  reasonable  length  of 
time. 

It  is  unsatisfactory  to  place  bad  material  in  the  hands  of  a  good 
workman,  for  he  will  never  take  an  interest  in  his  particular  job, 
and  logically  it  is  waste  of  time  tor  both  employer  and  employee. 

If  good  material  is  given  to  a  boatbuililer.  it  becomes  an 
I  incentive  for  him  to  turn  out  better  work. 

Planking  cannot   be  scamped.     Piecework   is  a  "  buybear  " 


134 


SHIPS'  BOATS 


to  honest  workmanship.  A  good  job  is  the  fiiat  conoMleiratioiiy 
and  speed  should  take  a  secondary  place.  If  one  can  onl^ 
secure  the  former  it  naturally  follows  that  speed  wiU  very  qiucldy 
follow. 

The  garboard  stroke  is  the  first  plank  adjacent  to  the  keel.  It 
is  sometimes  called  the  sandrstrake^  and  is  worked  from  tiie 
stempost,  forward  to  the  stem,  so  that  the  outer  edges  of  the 
scarph  butts  lie  aft,  and  are  thus  protected  when  the  boat  is 
movin<{  forward  through  the  water.  The  method  is  shown  in 
Fig.  oIBa.  The  garboard  planks  require  careful  fitting  at  the 
ends  of  the  boat,  and  together  with  the  adjacent  planks  have  a 


-CLAMP- 


-BQSS  PUNCH  — 


^ 


ctcyATioH        -roove:  set- 
" " "  """""""^^=»       CZ2) 

END  SECTION 
OFHEAVYSET  HEAVY PUI^H  OR 'bOLLV*' 


Fio.  55. 


Fio.  56. 


great  influence  on  the  rest  of  the  planking  as  to  maintaining  a 
good  form. 

Tlie  planks  are  held  in  position  ready  for  securing,  by  the 
aid  of  clamps  or  tangs,  as  illustrated  in  Fig.  50.  Particular  care 
should  be  exercised  in  drilling  the  holes  for  the  fastenings.  The 
bitt  must  be  kept  square  to  the  planking,  otherwise  the  nail  is 
brought  too  near  the  landing  edges.  This  precaution  is  veij' 
necessary  in  way  of  the  bilge. 

After  the  nails  arc  driven,  the  rooves  are  placed  over  the 
point  of  the  nail  and  hardened  home  against  the  planking  with 
the  aid  of  a  boss  ]>unch  (see  Fig.  56). 

The  whole  of  the  plank  fastenngs  between  the  timbers,  and 
also  the  timber  fastenings  within  arm's  reach  can  be  rooved  and 
clenched  by  one  man  with  the  aid  of  the  heavier  type  of  boss 


I 


CONSTRUCTION   OF  CLASS   1a   OPEN   LIFEBOATS     135 

punch.  The  roove  is  inaerted  over  the  uail  point  with  the  punch 
on  the  roove.  By  strilcing  the  head  of  the  nail  squarely  v.-ith  a 
light  hammer  the  weigJit  of  the  punch  drives  home  the  roove 
against  the  plank.  The  projecting  point  of  the  nai]  is  nipped  with 
the  pincers  to  within  |*'j  in.  of  the  roove,  and  the  heavy  clump  end 
of  the  boss  punch  is  then  held  on  the  nail  he^d  and  the  clenctiing 
completed  with  the  li^ht  hammer. 

The  rooving  and  clenching  of  the  timber  fastenings  from  the 
bilge  to  keel  is  a  double-handed  process,  one  person  holding  on 
the  head  of  the  nail  with  a  fairly  heavy  and  Hat-headed  hammer, 
while  the  roove  is  driven  home  and  the  nail  clenched  from  the 
inside  of  the  boat  by  another  person.  The  hghter  type  of  boss 
punch,  shown  in  Fig.  5(i,  is  used  during  this  operation. 

In  mahogany,  teak,  and  wych  elm  planking,  a  ahghtly  deeper 
countersink  is  given  to  the  drilled  hole  in  the  face  of  the  plank 
than  when  using  yellow  pine  and  larch,  to  accommodate  the  head 
of  the  nail.  The  main  thing  to  avoid  is  the  breaking  of  the  surface 
of  the  plank,  so  that  the  head  of  the  nail  lies  flat  on  the  surface  of 
the  pliuik, 

Too  much  eraphaaia  cannot  be  given  to  the  matter  of  plank 
fastenings ;  it  is  one  of  the  most  important  items  connected  with 
boatbuilding,  and  yet  so  many  firms  content  themselves  with 
allowing  boys  and  young  girls  to  undertake  the  work.  The 
practice  of  sinking  the  heads  of  the  plank  fastenings  below  the 
face  of  the  plank  is  shoddy  and  pre-historic  ;  regulations  should 
be  made  to  prevent  the  practice  from  continuing.  In  fairness  to 
the  boatbuilders  of  known  repute,  these  important  details  ought 
to  be  embodied  in  the  governing  specification,  for  in  many 
districts  the  standard  is  set  by  the  firm  who  is  not  so  particular 
in  the  main  essentials,  which  make  all  the  difference  between  a 
boat  and  a  basket. 

Itisavery  objectionable  practice  t<>  sink  theheadsof  the  plank 
and  timber  nails  beyond  the  surface  of  the  planking.  The  plank 
fastenings  are  usually  rooved  and  clenched  in  the  one  operation, 
and  the  timber  fastenings  are  driven  into  the  plank  and  timber, 
but  are  not  rooved  and  clenched  until  the  thwarts  are  fitted  and 
the  boat  stifiened  up. 

The  purpose  in  sinking  the  nail  heads  is  to  allow  for  the  final 
dressing  of  the  planks,  but  this  is  often  caiTied  to  excess  in  the 
effort  to  save  copper.  With  this  method  it  is  impossible  to  ascertain 
whether  a  timber  nail  is  properly  hardened  up  and  clenched. 
In  hardening  up  the  naU,  unless  particular  care  is  exercised, 
I  it  ia   bent,   and   the    fact   of    driving   the   head   of   the   niul 


136  SHIPS'   BOATS 

beyrmd  a  prriper  countersink,  and  forcint;  its  way  through  the 
material,  i^  re.spon.sibIe  for  many  split  planks.  The  whole 
operation  lends  itself  to  farelesi>nesc>  and  roui:h  work. 

A  far  .superior  practice,  and  one  that  should  be  enforced  bv 
re<^latioas.  is  to  dreas  the  planks  by  hand,  and  when  drilling 
the  planks,  to  so  arrange  the  bift  or  gullet  that  a  very  slight 
cr)untersink  is  taken  out  of  the  plank  surface,  and  only  just  suffi- 
cient as  to  brini!  the  nail  flush  with  the  surface  of  the  plank. 
When  the  point  of  the  nail  is  clenched  over  the  roove,  it  draws 
the  plank  landin;^.s  together,  because  the  head  of  the  nail  has  a 
proper  bt»arin_'  and  is  not  drawn  through  the  surface  of  the 
material.  A  slack  fastening  is  thus  very  quickly  discovered  and 
remedied.  This  practice  necessitates  care,  and  hammer  marks 
on  the  plank  surface  should  be  avoided.  All  that  is  necessary  to 
comjiletc  the  surface  is  the  use  of  sandpaper.  The  nail  heads  are 
left  bare  and  no  putty  Ls  therefore  recjuired. 

Some  shipowners  insist  on  this  method  in  the  construction  of 
boats,  and  it  is  a  practice  which  has  been  in  operation  with  the 
Admiralty  for  manv  vears. 

The  plauk  scarphs  are  about  -IJ  in.  in  length,  and  secured  with 
two  rows  of  copper  nails  clenched  on  hkivcs.  The  Admiralty 
practice  for  pullin;i  boats  built  on  the  "  clinker  "  system,  is  to 
secure  the  butts  with  one  row  of  copper  nails  plyed  over  on  the 
inside  surface  of  the  plank  at  the  after  ed<re  of  the  scarph,  and  a 
second  row  plyed  over  on  the  outside  surface  of  the  plank  at  the 
forward  vd'^n  of  the  scarph. 

When  tlie  fast«'ninizs  are  sunk  below  the  plank  surface  for 
final  <lressin^',  the  onlinary  scarph  butt  is  often  mined  by  the 
iiniount  of  material  j^laned  away  in  the  vicinity  of  the  row  of 
nails  at  the  after  ed^^e  of  the  scarph. 

To  strenizthen  the  butt  connections,  some  firms  fit  a  stout 
doublin;^  b(»hind,  connextiiiLT  two  timbers,  the  butt  fastenings 
beinir  roovc^d  and  ch^nched  on  the  doubling,',  as  sh(>wn  in  Fig.  57. 

The  f)lain  scarph  butt  is  tin;  method  which  creates  the  least 
amount  of  labour,  but  it  is  inferior  to  the  cJuHrd  butt.  The  latter 
method  must  be  carefully  undertaken  when  cutting  the  check  out 
of  the  |)lank.  t.o  pnjvent  the  saw  sinking  too  deeply  into  the 
pljink.     The  two  mt^thoiis  {ire  illustrated  in  Figs.  58  a  and  B. 

.\n  old  practire,  but.  nevertheless,  a  good  one,  is  to  insert  thin 
brown  paper  or  canvas  steeped  in  boiled  linseed  oil,  between  the 
faying  surfac<»s  of  the  scar[)h.  which  ensures  a  watertight  con- 
niu'tion.  provided  good  securities  are  also  made.  In  any  case  the 
faying  surfaces  should  be  well  treated  with  oil  paint. 


CONSTRUCTION  OF  CIA8S  Ia  OPEN  LIFEBOATS     137 

A  proper  shift  of  huUs  should  be  given  to  the  planks,  and  it  is 
usual  to  try  and  arrange  for  not  more  than  one  butt  in  a  strake. 


m 


3 


O  :    :      o  o 


r  f 


I 


o  o 

O  o 


—  .....  .^^ACtb^t*  ^  A€.€.tA^^.Ju^tUIA,<J!JU.A.K£€>t^Ie^A 


LyJ 
win 


^1 


Fio.  67. 


In  boats  of  19  ft.  and  downwards  it  is  quite  common  to  complete 
the  planking  without  a  butt  in  any  one  strake. 

There  should  be  at  least  three  planks  between  the  butts  in  the 
same  timber  space,  and  butts  in  adjacent  strakes  must  not  be 
nearer  to  each  other  than  3  ft.  It  is  also  advisable  that  the 
butts  of  the  garboard  strakes  should  be  properly  shifted,  for  the 
common  practice  is  to  fit  the  butts  in  the  same  timber  space,  so 
that  the  planks  on  the  port  and  starboard  sides  can  be  prepared 
on  the  bench  at  the  same  time,  i.e.  the  lengths  of  the  planks  on 


Arr 


LAI^^€0  SCA^P^ 


cneofeDsaufpH 


B 


Fio.  6S. 


both   sides    of    the   boat  in  a  particular  strake  will  be   the 
same.     No  plank  should  be  less  than  6  ft.  in  lengthy  and 


_  'jr 


i»!^iT? 


-..-•       :  :i  •  "    -  :  :  :.  :i>  i.  v:i  -    i^  ri.  4ai£  I$S-W.G.  for 


.(t 


TsZ'.  «v 


:.  :■-  -  •;.-•:  v_-i  ":.-  :•  ..:v:..rL>  :  :•  oti'i:  cers  ^ecome  more 
,;.■■--  .-::.  :.  ...  ■  _-:  --.-"  ::  r.:  :he  "old-time" 
;:-•:.      ■      '       :.-*    .  v         ^   :  -r^.:.,    :..  :-   -u:<:aiiial  wiU   be 

'-,i/.-i:       '     *'.-    -     -     .'.-*  1 -■-■        •  :•»>  ^',.-'  '^     ■    {w% 

'/:.■:  ••  :-:     :   :  .:.—--.    ::    :.   :.    :Lr  Adn-iraltr  for  all 

;/  ....u:^  %  .-4--    :.;   v.  :■  -   i  r^:     .--:^:  :  Ta:.:.«  -.:::.i.:e  to  the  plank 

'i:':  .';.*•;' a:*'...-  ; i. •.»•:.■ -;  -:.• -.v:.  ::.  F:..  "V*  {■:..•  vides  a  roove 
'.i'fi  ■'#  Ml':  4rj  -'i.'r  r.vi*  '.v-.^Li  ::.v  :.a:!  :-  i!vi:iLed  over,  the 
/'/'/v«;  -jf,K-,  jjiVi  tij*r  piriiir:  ci:.«.i  \vry  . ::-:.  s:.lir,<.  Fii:.  tjli  shows 
jifi  if/iji. "/•/«•']  roov#-  wiiir-h  i<  -lijiitiy  ci.'iiwx  and  of  heaWer 
.■.'.;i/itlif,:/  .,/,  tijat  w-}i<;rj  tli..'  u-t»:-iiin_  \<  rl.-neheil  up,  the  whole 
.!'i/f;i/.«r  #if  t.h«:  ////,•.'<;  jr  taKifj:.'  a  lull  bt-ariu:.  "U  the  jilaiik. 

'  ;if"fijl  atNrf,t.ii,ri  A\u\\\i\  be  driven  to  tht*  method  of  forming 
tiii/|  .•.«/iniri;/  th«:  h^d-nuU  of  plankiiiL'.  With  at  least  3  in.  of 
Uvfux'j  ^MxUu'M  t,ii  til*!  aj>ron  and  deadw.KHl.  ample  bearing  is 
Kiv«:ij  ioi  t)|f:  fJouMi:  row  of  fa.-tenini'.s. 


'CONSTRUCTION  OF  CLASS  U  OPEN  LIFEBOATS     139 


1 

^P  In  boats  of  24  ft.  in  len<^th  and  uvcr.  braas  screws  am  placed 

^     in  the  row  nearest  the  rabbet,  so  aa  to  provide  for  a  good  security 

when  caulking  the  "  hood-ends,"  tot  with  ordinarj'  copper  naits 

the  tendency  of  the  cauik  would  be  to  lift  them.     The  inner  row  is 

oE  copper  nails. 

Boats  below  24  ft,  in  length  have  the  planks  at  the  "  hood- 
I  ends  "  secured  by  a  double  row  of  nails,  slij^btly  reeled  to  prevent 
,  the  splitting  of  planks.     These  nails  are  usually  roser-beaded. 

It  is  not  sufficient  to  simply  cbampber  off  the  edge  of  the  stem 

or  stempost  to  house  the  "  hood-ends  "  of. the  planks.     A  proper 

rabbet  must  be  taken  out,  leaving  at  least  ]■'[  in,  of  solid  wood, 

I  80  that  the  pknk  takes  a  bearing  on  the  stem  and  stempost, 

I  which  provides  an  efficient  caulking  seam,  otherwise,  if  only  a 

1  chamfer  is  taken  off,  one  is  continually  caulking  into  the  seam 


Fio.  61. 
Method  of  aeoi 


■ing  liood-cnds  of  planks. 


I  between  the  apron  and  the  stem  or  stempoat.     An  illustration 
\.  of  the  method  referred  to  is  shown  in  Fig.  62. 

One  of  the  disadvantages  of  fitting  a  stem  and  apron  in  one 

E|iiece  of  timber,  is  discovered  when  it  is  necessary  to  renew  the 

■item  or  stempost,  and  for  this  reason  it  is  essential  that  both 

C0W8  of  fastem'ngs  should  be  in  the  apron.     There  is,  therefore, 

little  advantage  to  be  gained  by  having  the  end  row  in  tbe  stem 

and  the  second  row  of  securities  in  tbe  apron. 

A  good  practice  is  to  cut  the  rabbet  for  the  sheer-strake 

beyond  tbe  ordinary  plank  rabbet  so  that  the  former  becomes  a 

means  of  protection  to  the  remaining  plank  seama  or  "  hood-ends." 

Tbe  landing  edges  of  the  planks  on  the  apron,  are  usually 

soaped  away  as  shown  tn  Fig.  63.  which  allows  the  full  thickness 

I  of  the  upper  edge  to  be  carried  out  to  the  stem  or  stempost. 
The  soaping  away  is  done  when  the  plank  is  fitted  in  place,  and 


IVl 


SHIPS'  BOATS 


ll«  whr.le  0/ tke  w<«xl  is  (Jtm  hOT  tl»  «|>i»r  ei- i —J,  j„v 
«  .h„  .he  pUd.  ,„rW  i»™di.«,v'S:^'XlS^»^ 
l»«m.,n.  This  .luipuw  ur.v  hu  to  b.  tot  oirfoDy  3Se  ud 
the  practice  15  a  doubtful  one  tor  eSciencT  aa  it  i,  _,  'JlI 
.Wl.  Unless  the  chisel  is  properl.T  ^d,"  i„  .md,  ^J^ 
u  taken  off  the  upper  edue  of  the  pUidi  .t  til.  «in»i.^rS, 
»n  eitent  that  when  the  caulldna  tool  is  used  it  ^ibthe  tern 
"■"'.t  the  »tem  apron.  In  any  case,  the  watettiiifiia,  Di»ctii»IlT 
•lefK-mLs  on  the  efficiency  of  the  caulk.  «""y 

A  .siip.Tior  method  of  completing  the  "  hood-ends  "  of  planb 
w  to  ta[«.t  or  chamfer  holh  planks,  so  that  at  the  stem  or  atasiinat 
rahto,  the  plank  landinas  ate  half  checked,  wUch  inoTiders 
ptojier  bearing;  for  the  screw  fastening  and  tjie  wjiole  cf  tiia 


i 


|,l.,.k.> 


yi».  ii3. 

M'tli'xlH  uf  nnujiini;  luK'd-cn'lii of  planke. 


:  wull  syrtii-od  together,  apart  from  their  connection 
iiliirifiti'iiis.  A  ;:noiJ  solid  ending  is  thus  provided  fop 
ttii!  iiin\Um'j.  *'"il,  and  this  method  is  yreatly  to  be  preferred  to 
ttn:  |iniit,ii«  of  Dtilysnapiri;.'  away  the  upper  plank  landing.  The 
opi-r!il,iiin  can  \i<;  dornr  tin  the  bench  before  the  plank  is  secured. 

H':UiTi:ni:i;  should  he  made  t*)  Fij^.  ti4.  The  advantages  refened 
to  an-  obtuiiK!)!  tit  a  -.'leater  extent  in  the  case  of  a  "  square 
Ht<-ni  "  hofit,  when  ending  the  jihinks  on  the  transom. 

Till!  writer  liaH  repeatedly  seen  evidence  of  the  value  of  CfU«fuUy 
"  iitteil  hood-ends.'  Fig.  i(J7  shows  a  lifeboat  of  Class  Ia  which 
wuH  damafjed  durin;{  the  opemtion  of  bein^  lowered  from  the 
|''*vit«  in  a  hurry,  after  the  vessel  had  been  torpedoed.  Coming 
•"Violent  contact  with  the  ship's  side,  the  gunwale  was  smashed, 
*hich  brought  Uh>  mucli  stress  on  the  securities  of  the  plaoka  to 
^  AproQ.    Thti  fastcuiQ{;s  were  ordinary  copper  nails,  but  the 


the  a 


I 


CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS     141 


endin<,'8  (rf  tlie  ptaoks  were  made  on  tlie  half-clieck  principle, 
so  that  when  tlie  planks  came  away  from  the  apnm  they  were 
well  held  together  and  prevented  from  ripping.  This  boat  waa 
safely  brouf^ht  to  port,  mainly  depending  on  the  air-cases  for 
buoyancy.  Hence  the  necessity  for  periodically  testing  the 
watertij^htnesa  of  the  buoyancy  tanks. 

Caution  should  be  particularly  observed  when  working  the 
planks  at  the  transom  of  a  "  square  stern  "  boat,  and  with  a  view 
to  providing  a  good  fayinf;  surface  for  the  plank  endings,  a  fashion- 
piece  should  be  worked  aroimd  and  well  secured  to  the  transom  by 
throujih  copper  fastenings  clenched  over  roovea,  which  allows  an 
ample  bearing  surface  for  the  double  row  of  fastenings.  This 
fashion-piece  should  be  quite  free  from  short  grain.  (See 
Fig,  116.) 

One  of  the  weakest  positions  in  a  aquare-atemed  boat,  and 
where  there  ie  the  greatest  difficulty  to  obtain  a  satisfactory 
security  for  the  plank  endings,  and  also  where  there  is  a 
tendency  for  the  plank  to  split,  ia  Immediately  under  the  counter 
or  just  below  the  heel  of  the  transom.  These  difficulties  are 
obviated  if  sliver  pieces  are  worked  between  the  deadwood  and 
transom,  and  well  secured  to  the  stempost,  which  provide  a  proper 
bearing  for  the  plank  just  where  it  is  most  needed.  The  sUver 
pieces  have  the  additional  advantage  of  preventing  the  accumula- 
tion of  dirt  behind  the  deadwood. 

Tlie  heela  of  the  fash  ion -pieces  are  made  to  butt  on  the  sliver 
pieces. 

It  is  possible  for  these  projecting  pieces  to  be  left  <)n  thu  stem- 
post when  cutting  it  to  shape  at  the  band  saw,  but  the  process 
ia  difficult,  the  common  practice  now  being  to  fit  them  separately, 
and  bed  the  faying  surfaces  in  whit«  lead  paint. 

The  matter  is  of  more  importance  than  this  explanation 
probably  conveys  to  the  mind  of  the  reader. 

The  method  referred  to  is  illustrated  in  Figs.  60  and  66. 
Considerable  care  needs  to  be  exercised  in  working  the  garboard 
and  the  two  adjacent  strakes  at  the  transom  and  stempost  of  a 
"  square-atem  "  boat,  so  that  they  may  be  gradually  eased  to  lie 
fair  to  their  work.  This  applies  particularly  to  the  garboard 
strake  in  the  smaller  type  of  boats,  as  the  plank  is  worked  from 
the  horizontal  almost  to  a  vertical  position. 

Fig.  65  A  shows  one  method  of  ending  the  garboard  plank  on 
the  stempost,  which  requires  very  careful  treatment  to  prevent 
the  plank  from  splitting,  when  driving  home  the  fastenings. 
It  poeaeesee  the  advantage  of  completely  covering  the  deadwood. 


i 


142 


SHIPS'  BOATS 


Fig.  65  B  illustrates  an  alt'emativo  method  which  allows  the 
garboard  to  lie  more  evenly  on  its  bearing  without  giving  an 
undue  amoimt  of  twist.  This  arrangement  is  practically  the 
same  method  which  is  adopted  in  ending  the  plank  on  a  double- 


FASHfON  r/£C£ 


ELEVATION 
Fig.  05. — Methods  of  ending  enrboard  plank  on  the  deadwood. 


bowed  boat.  The  garboard  in  this  case  does  not  fully  cover  the 
deadwood,  and  it  is  nexjessary  to  fit  two  additional  stopwaters, 
but  it  «:(ives  great  advantage  to  the  boatbuilder  in  preventing 
split  planks  at  this  position. 

TJic  planks  at  the  turn  of  the  bilge  are  kept  as  narrow  as 
possible  to  enable  the  minimum  amount  of  soloing  being  taken 


I 


CONSTRUCTION    OF  CI^SS  U  OPEN   LIFEBOATS    143 

off  the  landinji  ettgcs,  but  sufficient  to  allow  tie  upper  plank  to 
lie  well  into  the  timber  without  uudiily  reduciaf;  ita  thickueas. 
{See  Fig  67.)  It  is  the  practice  in  some  yards  to  slightly  increase 
the  thjckness  of  the  material,  because  there  is  no  doubt  an  area 
of  we-akness  exists  in  way  of  the  bilge,  which  is  restored  U) 
some  extent  by  the  fitting  of  bilge  keelsons. 

The  use  of  section  moulds  facilitates  the  operation  of  securing 
a  satisfactory  job  with  the  eoleing  of  the  plank  landittga.  Care 
should  be  exercised,  particularly  just  beyond  tJie  quarter  sections 
towards  the  ends  of  the  boat,  where  the  bend  in  the  plank  is  the 
greatest.  Insufficient  attention  is  often  given  to  the  process  of 
soleing  or  chamfering  the  plank  landings,  to  such  an  extent  that 
some  firms  reiy  on  a  thread  of  cotton 
being  caulked  into  the  seam  to  secure 
watertightness.  With  fastenings  sunk 
below  the  surface  of  the  plank,  this 
practice  is  undesirable,  for  when  the 
cotton  swells  the  strain  draws  the 
fastenings  a  still  greater  distance 
through  the  phmk,  the  boat  is  left  in 
a  weaker  condition,  and  no  advantage 
is  gained  from  the  point  of  view  of 
watertightness. 

As  each  plank  is  worked,  the  landings 
are  well  coated  with  good  thick  oil-paint. 
Provided  the  planks  are  secured  in  the  section 

proper  manner,  a  very  good  practice  is  pm.  (Hi. 

to  coat  the  landings  with  a  composition 
called  blaiT,  which  is  made  up  of  Hock 

and  Stockholm  tar.  MesHrs.  Alfred  Holt  and  Co.,  of  Liverpool, 
take  a  very  keen  interest  in  the  construction  of  lifeboats  for 
their  vessels,  and  they  insist  on  blair  being  used  for  the  piirpose 
referred  to. 

One  cannot  expect  to  secure  larch  without  knots,  although 
when  visiting  an  estate  at  Ardentinny,  Loch  Long,  the  writer 
inspected  some  timber  cut  from  very  tall  trees  whose  branches 
were  at  a  great  distance  from  the  groimd,  and  there  waa  hardly  a 
knot  to  be  seen  where  the  material  was  cut,  being  magnificent 
specimens  of  the  Scotch  larch.  Unfortiinately,  the  large  bulk 
of  the  material  which  builders  have  to  handle  does  possess  knots, 
and  these  must  be  considered.  Planka  which  have  large  black- 
edged  knots  must  be  taken  out  of  the  boat ;  but  within  reason, 
knots  can  be  dealt  with  by  fitting  doublings  behind  them  and  so 


I 


144 


SHIPS*  BOATS 


arrani^ocl  as  to  catch  two  timbers.    These  doublings  should  be 
w«'ll  bedilt'd  in  thick  white-lead   paint  and  secured  by  copper 


soi,E:/Afc 


Fn;.  ♦»7.-    Section  showing  plank  soleing. 

nails  clonchod  over  moves.     Thev  must  be  fitted  and  secured 
bef(ne  the.  j)laiikinL^  is  completed.     (See  Fig.  68.) 

Lairh  is  a  very  »:(K)d  material  for  planking  boats  carried  on 
vesst*ls  eni:ai:ed  in  trades  which  do  not  take  them  through  the 
tropics.  It  is  resilient  and  touirh,  but  like  wj'ch  elm  it  needs  to 
be  closely  fastened,  as  there  is  a  tendency  to  warp.  Turpentine 
is  olitained  from  larch,  so  that  the  latter  possesses  certain  natural 
(jnalities  which  protect  the  boat  from  the  weather. 


fiij'J 


-  ~x- 


.7"//V7^^/? 


r--r 


s- 


''>l^ 


-A 


O 
---♦•-   - 


n/TA^Or 


o 


•^  '  ' ' '  ■  '  '  '  ....,.■■ 


k^'w 


PLA/^A 


A 


O     I 


OOoBl/MSj 


U 


V^iuJ 


/'lA/y/r 


ELEVATION  SECTION 

Fifl.  (38. — Method  of  fitting  doubling  Whind  knots  in  planking. 


The  larger  tlie  tree   tlic   more   brittle   bix^omes   the  larch, 
although  it  will  probably  have  a  greater  freedom  from  knots. 


i 


I 


CONSTIUICTION    OF   CLASS   Ia   OPEN   LIFEBOATS     H5 

ITiere  is  more  resilience  and  etrengtli  in  a  reasonable  sized  tree, 
although  in  the  very  narrow  trees  there  is  too  much  sap  and 
the  heart  wood  is  not  in  mature  condition.  Old  boatbiiilders 
constructing  fishing-boats  are  always  particularly  anxious  to 
secure  "  one-plank  trees." 

Yellow  pine  and  silver  fir  make  very  good  boats,  provided 
the  vessels  do  not  trade  in  climates  of  great  heat. 

Boata  are  much  lighter  when  built  of  these  species  ol  wood, 
and  they  very  quickly  "  take  up  "  when  placed  in  the  wat«r. 

It  ia  qidte  unreasonable  to  expect  that  material  grown  in 
northern  or  temperate  climates  will  stand  the  extreme  heat  of 
the  tropics.  Sufficient  experience  from  ships'  officers  and  in- 
dpectors  only  goes  to  strengthen  the  suggestion,  that  lifeboats 
carried  as  a  part  of  the  statutory  equipment  of  foreign-going 
vessels  whose  trade  carries  them  tiirough  climates  of  gre^it  heat, 
should  be  constructed  of  mahogany  or  teak,  and  preferably 
the  latter. 

The  lifeboats  supplied  by  Messrs.  Caiid  and  Co.  {now  Mcsai's, 
Harland  and  Wolff,  Ltd.),  of  Greenock,  for  vessels  owned  by  the 
Peninsular  and  Oriental  Steam  Navigation  Co.,  Ltd.,  have  lasted, 
in  many  cases,  for  twenty  years,  or  even  a  greater  length  of  time. 
These  boats  are  constructed  of  two  thicknesaes  ot  mahogany, 
and,  it  ia  almost  superflnous  to  add,  they  were  not  completed 
under  conditions  of  piecework. 

A  specification  may  be  complete  ia  every  detail,  and  drawn  up 
with  the  exj>ress  purpose  of  ensuring  that  the  boats  are  con- 
structed to  the  highest  class,  but  imlcss  the  material  has  been 
thoroughly  seasoned  it  onlj   results  in  waste   of   money  and 

The  view  point  of  the  average  boatbuilder  is  somewhat 
Ited  88  to  the  actual  conditions  of  service  of  a  vessel, 
so  fat  as  they  influence  the  life-saving  equipment,  and  it  is  only 
the  ahip's  officer  or  surveyor  who  comes  into  contact  with  the 
difficulties  and  is  able  to  secure  the  experience,  that  enables  him 
to  express  an  opinion  as  to  what  should  be  carried  out  to  meet  the 
actual  requirements. 

The  operation  of  planking  is  of  the  greatest  importance,  both 
in  regard  to  quality  of  material  and  standard  of  workmanship, 
and  it  ia  hoped  in  future  that  greater  care  will  be  exercised  by 
those  employed  in  the  boat  yards  to  prevent,  as  far  as  they  are 
able,  the  necessity  of  a  ship's  boat,  after  it  has  been  in  service  for 
three  months,  being  covered  on  the  inside  with  two  or  three  coats 
of  plastic  or  bitumastic  enamel  before  it  can  be  brought  back  to 


146  SHIPS*  BOATS 

a  condition  of  waterti^htness  and  fulfil  the  purpose  for  which  it 
was  constructed. 

As  soon  as  the  planking  is  in  a  condition  to  receive  the 
timbers,,  the  inside  surface  is  <^ven  a  good  soaking  coat  of  white- 
lead  paint  (without  the  application  of  a  disproportionate  amount 
of  drj'crs),  or  boiled  linseed  oil. 

Timbers. — The  regulation  distance  between  the  timbers, 
from  centre  to  centre,  is  six  inches.  Sufficient  reason  has  already 
been  given  for  the  necessity  of  preserving  a  high  factor  of  safely 
in  regard  to  scantlings.  The  comparison  between  the  scantlings 
of  boats  coiLstructed  under  Admiralty  supervision  to  a  detailed 
specification,  and  those  built  to  the  requirements  of  the  mercantile 
marine,  will  serve  no  useful  purpose,  as  the  conditions  of  service 
in  the  two  cases  are  vastly  different. 

The  sizes  of  the  timbers  shown  in  Table  XIV.  are  given  on  the 
assumption  that  they  are  w^ell  rounded  on  the  iimer  surface. 
The  section  is  considerably  lightened  without  reducing  the 
strength,  and  they  can  be  workcxl  into  position  with  less  difficulty 
than  if  the  timber  manitaincd  a  rectangular  section. 

The  position  of  the  timbers  are  marked  on  the  planking  from 
the  indications  already  given  on  the  hog-piece,  also  those  of  the 
rising  and  the  bilge  stringer,  to  enable  the  sliver  pieces  between 
them  and  the  timbers  to  be  tacked  in  their  correct  position.  If 
the  gunwale  is  of  the  '*  box  "  type,  the  tapered  liner  behind  the 
sheer  strake  is  also  fitted  in  place.  Care  is  taken  to  see  that  all 
doublings  are  fastened  and  clenclied.  The  planking  is  then  in  a 
condition  to  receive  the  timbers.  The  timbers  at  the  ends  of  the 
boat  are  sj)aced  slightly  less  than  0  in.,  to  allow  for  the  flare-out 
at  the  gunwale,  and  tlit;  heels  of  those  which  cannot  be  worked  in 
one  j)iece  across  the  niithlle  line  are  checked  into  the  deadwood, 
as  shown  in  the  photograj>h  of  Fig.  4.*). 

Tinil)ers  are  usually  made  from  American  elm,  owing  to  its 
close  strainht  i^rain  and  elastic  nature.  Oak  and  ash  are  also 
permitted,  but  the  latter  is  trrated  with  suspicion  by  some  boat- 
buildrrs  jis  being  inclined  to  rot  at  the  extremities.  During  the 
])eriod  of  the  war  certain  substitutes  had  to  be  usihI  for  the 
ai)j)roved  materials,  but  after  tin'  honn*  timber  supply  had  been 
organised  there  was  little  need  for  use  of  tlu^  substitutes,  as  far  as 
th(»  timbers  were  concerned.  AVvch  elm  of  straight  grain  was 
occasionally  used,  and  also  Jiome-grown  English  elm,  but  the  latter 
wa,s  more  trouble  than  it  wa^s  worth,  since  for  every  timber 
secured  in  position  two  were  broken  and  cast  out. 

The  extra  cost  of  rounding  the  timbers  is  very  small,  as  the 


CONSTKUCTION  OF  CLASS   Ia  OPEN  LIFEBOATS     U7 

process  is  quickly  performed  with  the  aid  of  the  spindle  machine, 
r>r  by  special  cuttera  inserted  in  the  planin|f  machine.  A  much 
lighter  appearance  ia  given  to  the  boat  and  the  full  faying  surface 
of  the  timber  is  preserved. 

Timbers  are  fitted  in  one  length  from  j.'unwale  to  fninwale. 

The  operation  of  timbering  ia  usually  commenced  from  aniid- 
shipa,  working  to  the  ends,  so  that  those  which  are  brolicu  during 
the  operation  of  bending  may  possibly  be  worked  in  at  the 
extremities  of  the  boat. 

The  holes  are  drilled  with  the  bit  through  the  plank  landings 
from  the  inside  of  the  boat,  care  being  taken,  especially  at  the 
turn  of  the  bilge,  to  keep  the  bit  aquare  to  the  surface  of  the  plank, 
otherwise  the  timber  fastening  will  be  too  close  to  the  landing 
edge.  With  a  ^-iu,  landing  there  should  be  no  difficulty.  The 
nails  are  inserted  in  the  planks  in  readiness  for  the  timbers 
when  brought  from  the  steam-chest. 

The  timber  is  usually  secured  at  the  centre  of  the  hog-piece 
by  a  galvanised  iron  nail,  and  carefully  worked  towards  the  gun- 
wale. A  fairly  heavy  hammer  is  used  for  holding  on  when  the 
nail  is  being  driven  from  the  outside  of  the  plank. 

Considerable  divergence  of  opinion  existed  at  one  time  as  to 
the  most  effective  means  of  securing  the  timbers. 

The  common  practice  in  most  districts,  before  the  standard 
instructions  came  into  operation,  so  far  as  boats  for  the  mercantile 
service  were  concerned,  was  to  ply  the  vails  over  on  the  inside 
surface  of  the  timber  while  the  latter  was  soft  and  pliable.  The 
method  may  be  a  successful  one  if  the  heads  of  the  nails  are  not 
simk  in  below  the  surface  of  the  plank,  but  it  often  occurs  that 
before  the  nail  has  been  completely  driven  home  against  the 
plank,  the  boatbuilder  inside  the  boat  has  started  to  ply  over  the 
nail  on  the  timber,  and  bends  it  in  the  operation,  having  used  the 
same  hammer  as  when  holding  on  to  the  timber  for  the  insei'tion 
of  the  fastening ;  this  practice  is  responsible  for  many  split 
planks.  If  the  timber  nails  are  finally  punched  below  the  surface 
of  the  pl&iik  they  are  either  bent,  nr  the  points  lose  their 
original  grip  of  the  timber,  when  the  latter  b  in  a  soft  condition. 

The  method  now  in  vogue  throughout  the  United  Kingdom 
is  t4i  clench  all  the  timber  fastenings  over  rooves  in  a  similar 
fashion  to  the  plank  securities.  The  clenching  operation,  of 
course,  camiot  be  done  when  the  timbers  are  insei'ted  straight 
from  the  st^am-chest,  but  there  should  be  no  need  for  tie  "  harden- 
ing up  "  process  as  previously  explained. 

The  method  ot  "  rooving  "  the  timber  nails  has  always  been 


1 


148 


SHIPS'  BOATS 


considered  to  be  essential  for  all  high-class  work,  but  where  no 
p;overnin<5  specification  is  in  operation,  it  is  natural  for  the 
boatbuilder  to  take  the  "  line  of  least  resistance,"  and  adhere  to 
the  "  plyed-over  "  method  of  securing  the  timbers,  which  saves 
him  the  cost  of  copper  rooves  and  a  considerable  amount  of 
labour. 

TABLE  XVI. 
Particulaus  of  OoFFica  Nails  akd  Rooyxs. 


S.W.CJ. 


1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 


Diameter  of  nail. 


Fract.iuns  of 
an  inch. 


ft 

ifuU 

i 

i  bare 

A  f  uu 

^]^  bare 

A  bare 
■  i  full 

i 

Jt  bare 


])ccinials 
uf  an  inch. 


•300 
•284 
•259 
•238 
•220 
•203 
•180 
•165 
•148 
•134 
•120 
•109 
•095 


Blillimctnw. 

7  •62 
7-21 
6-58 
604 
550 
616 
457 
419 
376 
3-40 
305 
277 
2-44 


Diamotcr 

of  roove. 

Indies. 


1'* 

i 

a 
n 

o 

iir 

A 
¥i 
U 
A 

i:i 
a" 


I 


Diameter 

of  hole 

in  roove. 

Inches. 


'324 
-324 
•276 
•276 
•252 
•252 
•212 
•185 
•160 
•160 
•144 
•128 
•116 


Thicknees 

of  roove. 

L.8.O. 


12 
12 
12 
12 
13 
13 
15 
15 
16 
16 
16 
17 
17 


if  done  properly,  as  explained  previously,  the  rooving  method 
is  much  to  be  preferred,  but  if  left  in  the  hands  of  boys  and  girls, 
all  it^  advauta^^es  vanish,  for  a  bad  clench  is  inferior  to  a  plyed- 
over  nail. 

The  timber  nails  are  of  a  8li«i:litly  heavier  gauge  to  the  plank 
fastenings,  and  each  nmst  have  a  flat  head.  Reference  should 
be  made  to  Table  XIV.  for  the  correct  gauge  of  nails  to  be 
used. 

Table  XVJ.  gives  particulars  of  copper  nails  and  rooves, 
showing  the  appropriate  diamet^jr  of  roove  tf)  be  used  with  the 
particular  gauge  of  nail. 

Taking  a  Class  I  a  lifeboat,  witJi  dimensions  26*0'  X  S'O'  X  3-25' 
and  15  strakes  of  planking,  constructed  on  the  clinker  prin- 
ciple, it  is  interesting  to  note  that  in  addition  to  the  fastenings 
in  the  combinations  of  the  frame,  such  as  stem,  stempost,  dead- 
woods,  hog-piece,  etc.,  some  five  thousand  five  hundred  and 
fifty  copper  nails  with  the  same  num])er  of  copper  rooves  are 
worked  in  the  planking,  timbers,  gunwales,  and  stringers.     The 


CONSTRUCTION   OF   CLASS  Ia  OPEN   LIFEBOATS    149 


total  weight  of  copper  nails  in  one  boat  of  these  dimensions  is 
about  37  to  38  lbs. 

The  writer  has  gathered  a  few  particulars  from  information 
supplied  to  him  by  The  Cartsbum  Lifeboat  Building  Co., 
Greenock,  which  gives  the  approximate  quantity  of  copper 
fastenings  required  in  the  26-ft.  lifeboat  of  standard  dimensions. 
See  Table  XVII. 

All  reference  to  cost  of  production  has  been  carefully  avoided. 
The  best  method  of  arriving  at  an  estimate  should  be  based  on  the 
cubic  capacity  of  the  boat.  Five  weeks  is  a  reasonable  length 
of  time  required  for  the  constniction  of  a  26-ft.  lifeboat  of  Class  Ia, 
with  two  journeymen  and  one  apprentice,  working  on  time  rates 
and  without  overtime. 

TABLE  XVII. 

Approximate  Number  of  Copper  Fastenings.    Open  Lifeboat  Class  Ia, 

Clinker  Build,  26  0' x  8  0' x  3-25'. 


Gauge. 

length. 

Inches. 

Inches. 

10 

^ 

10 

2i 

10 

3-3i 

12 

U 

12 

1 

Where  used. 


Timbers. 

Garboard.  and  hood-ends. 

Stringers,  risings,  and  gunwales. 

Planks. 

Scarphs. 


No.  to  the 
lb. 


110 
137 
80 
240 
300 


Quantity. 


15  lbs. 

2  lbs.  2  07.S. 

3  lbs. 

12}  lbs. 

lib. 


Total  number  =  6550.     Total  weight  =  34  lbs. 

Carvel-built  Boats. — An  alternative  method  of  planking  a 
boat  is  by  working  the  planks  edge  to  edge,  having  their  surfaces 
flush  inside  and  out,  as  illustrated  in  Fig.  55.  The  majority  of 
motor  boats  and  high-class  pulling  boats  are  constnicted  on  this 
principle  or  the  double-skin  method. 

A  "  carvel "  built  boat  is  stronger  than  a  boat  constructed 
on  the  "  clinker  "  principle.  In  the  first  place  it  is  essential  to 
use  a  greater  number  of  moulds,  and  in  the  majority  of  cases, 
they  have  to  be  prepared  from  the  faired  sections  on  the  scrieve 
board.  They  are  built  up  as  shown  in  Fig.  70,  and  as  soon  as  the 
combinations  of  the  frame  of  the  boat  are  secured  together  and 
erected,  the  section  moulds  are  placed  in  position  and  well  secured 
by  fore  and  aft  ribbands  placed  on  the  upper  edges. 

It  will  be  noticed  that  the  moulds  are  made  to  the  outside  of  the 
timbers.  A  suitable  number  of  ribbands  are  fitted  fore  and  aft 
from  stem  to  sternpost,  which  gives  the  correct  form  of  the  boat 
at  the  inside  surface  of  the  planking. 


150 


SHIPS'  BOATS 


The  si^aatlia»B  of  tlie  timbers  can  be  reduced  without  detriment 
Ui  the  boat  by  a  I  in,,  both  inouldLxl  aud  sided,  from  the  particulais 
given  in  Table  XIV. 

The  timbers  are  then  steamed  and  bent  round  to  the  inside 
ol  the  fore  and  aft  ribbands  and  temporarily  secured  to  the  latter. 

The  outside  surface  of  the  timbers  and  the  fayin^;  edges  of 
the  planks  are  coated  with  white-lead  paint  as  the  work 
pronreaaos. 

Special  care  must  of  necessity  be  exercised  in  fitting  the  plank 
edf^es  in  order  to  preserve  a  watertight  jouit.  In  fine  work  these 
are  worked  close  together,  but  in  heavier  boats  a  alight  chamfer 


is  given  to  allow  for  a  thread  of  cotton  to  be  caulked  into  the 
seam. 

The  motor  boat  in  course  of  construction  shown  in  the 
photograph  at  Fig.  142  waa  timbered  on  this  principle. 

Tlic  planks  ate  secured  to  the  timbers  by  copper  nails  cleiiched 
over  rooves,  one  row  at  each  edge,  care  being  taken  that  when  the 
nails  are  driven  into  tJie  timbers  the  direction  is  such  that  it 
will  have  the  tendency  to  close  the  seam.  The  process  of  clench- 
ing the  fasteningis  can  be  completed  as  each  plank  is  worked. 

The  usual  precautions  which  must  be  observed  in  planking 
a  "clinker"  built  boat,  and  already  ejcplained  in  some  dctaO, 
apply  to  a  boat  built  on  tlie  "  carvel  "  principle.  With  the  former 
the  timbers  are  bent  when  the  boat  is  planked,  and  with  the 
latter  they  are  usually  bent  before  the  planks  are  worked.  The 
practice  varies  in  different  districts,  but  the  writer  is  inclined  to 
tliiuk  that  a  fairer  boat  is  produced  by  the  method  described. 

As  the  planks  are  secured  to  the  timbers,  so  the  ribbands  are 


CONSTRUCTION   OF  CLASS  Ia  OPEN  LIFEBOATS    151 

removed  from  tlie  moulds.  The  rubbers  ftre  usually  fitted  direct 
to  the  timber  as  shown  in  Fig.  55. 

Doable  Skin  Boats. — The  highest  class  of  motor  or  pulling 
boats  is  constnicted  with  two  skins,  having  a  waterproof  fabric 
between.  Provided  the  material  is  well  seasoned  and  of  suitable 
quality,  there  is  no  reason  why  the  lifeboats  should  not  last  the 
life  of  the  vessel. 

There  are  at  least  two  methods  of  working  the  planking,  but 
other  methods  will  also  be  referred  to  when  dealing  with  the  con- 
struction of  pontoon  lifeboats  and  open  lifeboats  of  Class  IIa. 

The  stronger  boat  of  the  two,  when  built  on  the  double  skin 
principle,  has  the  inside  and  outside  strakes  of  planking  running 


^>!^^^^^ 


WATKIV  ^^4>or  LIMKN    AC 


^       —    -, — 


Fia.  71.  Fio.  72. 

Methods  of  working  tho  planking  of  double-skin  boats. 

at  45°  with  the  keel,  but  each  in  the  opposite,  direction,  so  that 
the  two  skins  cross  each  other  at  right  angles.  This  method  is 
illustrated  in  Fig.  71. 

The  second  method,  shown  in  Fig.  72,  consists  of  an  inner 
skin  with  strakes  of  planking  running  aft  at  45*^  to  the  keel,  and 
an  outer  skin  with  strakes  running  fore  and  aft  as  in  a  '^  carvel  " 
built  boat. 

In  both  cases  waterproof  linen  is  worked  between  the  two 
skins. 

Practice  varies  in  diflfercnt  districts  throughout  the  United 
Kingdom.  The  writer  will  therefore  confine  himself  to  a  brief  de- 
scription of  the  method  of  planking  a  double-skin  boat,  constructed 
on  the  diagonal  principle,  which  has  come  under  his  immediate 


SHIPS'  BOATS 

ntitit-e  in  the  yards  of  Messrs.  Dickie  and  Sons,  Tarbert,  Loch 
Fyne,  and  Messrs.  Caird  and  Co.,  Greenock  (now  Messi^.  Harland 
and  Wolff,  Ltd.). 

Boats  with  small  dimensions  (up  t^^i  22  or  23  ft.  in  leji^ith)  can 
be  constructed  on  tlie  "diagonal"  principle,  having  moulds 
built  up  as  shown  in  Fig.  70,  a  description  of  which  has  already 
been  given  when  dealing  with  "  carvel  "  built  boata.  When  it 
comes  to  boats  of  larger  dimensions,  the  moulds  are  made  of  more 
Rubatantial  material,  and  not  of  the  us\ial  "  mould  stuff."  They 
are  made  to  the  inside  of  the  timbers,  and  carefully  checked  with 
the  lines  on  the  ilfHir  or  scrieve  board. 

The  ram  or  frairu;  i.e.  the  stem,  keel,  stempoat,  with  hog, 
deadwoods,  etc.,  having  been  erectwl  in  position  and  made  to 
plumb  the  keel-board,  with  the  stem  and  stempost  outwinding, 
the  whole  is  rigidly  secured  to  prevent  any  movement  during  the 
early  stages  of  construction. 

The  moulds  are  then  placed  in  position,  plumbed,  and  set  up  in 
conformity  with  the  line  of  keel,  stem,  and  stempost.  The  head- 
board is  fixed  and  secured  by  shores  from  the  overhead  structure. 
The  moulds,  therefore,  practically  become  fixtures,  and  are  not 
removed  until  the  boat  is  planked,  tinibored,  and  gunwales  secured. 
Reference  should  be  made  to  Fig.  69  for  an  fllustration  of  the 
moulds  referred  to. 

Now  comes  the  feature  of  constniction  where  practice  differs 
according  to  the  tastes  of  various  builders,  but  the  following 
is  considered  to  be  the  simplest  and  best  arrangement  of  planking. 
The  moulds  being  made  to  the  inside  of  the  timbeis  and  fixed 
in  position,  good  stout  ribbands  are  worked  fore  and  aft  and  let 
into  and  secured  to  the  moulds,  so  that  the  outaide  surface  of  the 
ribbands  are  flush  with  the  edge  of  the  moulds.  The  necessity 
for  stout  moulds  is,  therefore,  obvious. 

We  now  have  the  longitudinal  shape  of  the  boat  given  by  the 
ribbands. 

It  is  usually  arranged  that  the  deadwoods  and  aprons  are  left 
slightly  larger  than  specified,  to  allow  for  their  being  trimmed 
fair  with  the  lines  of  the  boat. 

The  timbers  are  spaced  about  9  in.  apart,  and  the  scantlings 
equal  to  those  shown  in  Table  XIV.  The  wider  spacing  is 
permissible  owing  to  the  additional  strength  received  from  the 
diagonal  planking.  They  are  now  steamed,  fixed  to  the  hog,  and 
clamped  to  the  ribbands  until  the  gimwales  are  worked.  The 
latter  are  aided  and  moulded  to  meet  the  specification  require- 
ments and  placed  in  position. 


CONSTRUCTION   OF  CTiASS   Ia  OPEN   LIFEBOATS    153 

The  gunwales  may  be  solid  or  of  the  "  box  "  type ;  if  the 
former  is  fitted,  the  timbers  and  inner  skin  of  planking  are  usually 
checked  into  the  gimwalc,  with  a  good  capping  piece  covering  the 
gimwale  and  tlie  upper  edges  of  the  outside  strakes  of  planking, 
as  shown  in  Fig.  79  c. 

The  planks  are  now  prepared  and  steamed,  while  an  abundant 
number  of  small  shores  are  placed  at  the  disposal  of  the  boat- 
builder  and  within  easv  reach. 

The  inner  skin  is  first  dealt  with  ;  these  planks  are  worked 
diagonaUy  at  an  angle  of  45°  from  the  line  of  keel.  The  upper 
ends  lie  aft,  they  are  worked  in  one  length  from  keel  to  gunwale. 
The  inside  surface  is  planed  before  working  so  that  a  slight  touch 
up  with  a  "  flat  scrape  *'  is  all  that  is  necessar}'  to  obtain  a  good 
inside  surface  on  the  completion  of  the  boat. 

As  the  planks  are  worked  they  are  secured  to  the  hog,  gun- 
wales, deadwoods,  and  aprons,  with  l|-in.  spikes,  sufficient  to 
keep  the  planks  in  position,  until  the  outer  skin  is  fitted. 

The  inner  skin  having  been  completed,  a  slight  chintz  of  boat- 
cotton  is  worked  in  each  seam  in  way  of  tlie  hog,  aprons,  and 
deadwoods,  this  precaution  being  ccmsidered  essential  for 
watertightnesso 

The  outer  surface  of  inner  skin  is  then  coated  with  good  white- 
lead  paint  and  waterproof  linen  stretched  thereon. 

The  operation  ol  working  the  outer  skin  is  commenced  and 
performed  in  the  same  manner  as  the  inner  skin,  except  that 
the  planks  lie  forward. 

The  short  shor(\s  referred  to  previously  are  used  for  keeping 
the  planks  in  their  correct  position  before  fasti^ning. 

The  two  skins  are  fastened  together  with  copper  nails  clenched 
over  rooves,  the  disposition  of  the  latter  being  ascertained  before 
the  planking  is  commenced.  The  securities  are  completed  as  the 
outer  skin  is  worked,  being  lined  oflF  by  the  person  responsible 
for  the  boat.  The  outer  skin  is  fastened  to  the  hog,  apron, 
stem,  sternpost,  and  deadwoods  with  spikes  or  brass  screws, 
and  to  the  gunwale  and  hog-piece  by  clenched  nails.  Figs.  73 
and  74  show  the  general  aiTangement  of  securities  in  way  of 
the  keel  and  apron  of  a  boat  constructed  on  the  "  diagonal " 
principle. 

From  four  to  six  floors  cut  from  material  grown  to  shape  are 
usually  fitted  in  the  large  pulling  boats. 

Throughout  the  operation  of  working  the  two  skins  particular 
care  should  be  exercised  to  avoid  "  pifffifig ''  or  "  liolidays,"'  i.e, 
there  must  be  a  perfect  fit  between  the  two  faying  surfaces. 


154 


SHIPS'  BOATS 


The  boat  at  this  particular  period  of  consinictiQn  appears  to 
be  ill  a  condition  of  chaos,  with  shores  inside,  outside,  and  on  top. 
These  arc  now  all  removed,  and  the  boat  canted  in  preparation 
for  dressing  or  cleaning-oflE  the  outside. 

When  working  with  mahogany  or  t«ak  a  slight  countersink 
Ls  made  in  the  plank  to  receive  the  fastenings  with  the  aid  of  the 
special  "  bit ''  or  "  gutter''  and  provided  the  tool  is  in  the  hands 
of  a  competent  ])oatbuilder,  the  nails  can  be  driven  home  without 
disfiguring  the  plank  by  using  the  heavy  type  of  boss  punch  or 
"  Mbjr 

It  may  be  necessary  to  harden  up  the  fastenings  at  the  stem, 
sternpost.  or  heel  seams,  and  the  latter  are  finally  caulked  with 
boat-cotton  and  j)uttied  by  means  of  a  "  putty  stick  "  which  is 
shaped  like  an  ordinary  sharpened  pencil ;   the  seams  are  thus 


,T  I M  8  f:  n 


"■'^"»^  .'«r«.K/|    '':.']'    /.r,s,o. '^vRA.e 


^  <^':>-^<< 


SECTION 
Fid.  73. 


PLAN 
Fio.  74. 


well  filled  and  the  work  more  efficiently  completed  than  if  the 
ordinary  j)utty  knifo  were  used. 

The  foregoing  remarks  briefly  describe  the  operation 
of  planking  a  '*  double  skin ''  boat,  and  as  previously  stated, 
different  district's  have*,  varitnl  nietliods  or  j)ractices,  but  the  details 
ref<M'red  to  ai'c  i'rnorjillv  adhered  to  on  the  (^lyde. 

Rising. — Having  described  the  methods  adopted  during  the 
construction  of  the  frame,  and  the  skin  or  plankijig  of  an  ordinary 
pulling  ])oat  of  ( -lass  1a,  attention  will  now  be  given  t(j  the  various 
details  associated  with  the  internal  fittings. 

The  **  r/'.s' /"?///,"  or  ''  wmrimjy  is  the  upper  stringer  which  runs 
fore  and  aft  from  the  stem  to  the  st(M'n])ost  apron,  forming  a  seating 
for  the  ends  of  the  thwarts  and  acting  as  a  lomritudinal  stiffener 
to  the  timbers,  distributing  the  stresses  which  come  upon  the 
thwarts  from  the  oarsmen  or  m<ast. 

The  mateiial  is  usually  of  Ameri(?an  elm  or  i>itch  pine.  Larch 
is  unsuitable  unless  quite  free  from  knots.     It  is  fitted  in  one 


CONSTRUCTION  OF  CLASS   Ia   OPEN  LIFEBOATS 


length.  Between  tlie  timbers  and  planking  tapered  liners  are 
secured,  which  provide  a  aolid  bearin;;  for  the  fastenings. 

The  risinji  is  secured  at  every  timber  and  to  the  planking  by 
copper  nails  clenched  over  rooves  and  worked  in  red  fashion. 

The  scantlings  should  not  be  leiss  than  1  in.  in  thickness,  to 
provide  a  proper  bearing  for  the  ends  of  the  thwarts  and  their 
securities,  and  not  leas  than  3  in.  in  width. 

The  back  of  the  riaiug,  or  faying  surface  to  the  timbers,  should 
be  painted  hnfore  being  secured  in  position. 

If  reference  is  made  to  Table  XVIII.  the  rising  can  always 
be  estimated  to  its  correct  position  in  relation  to  the  gunwale, 
which  will  allow  the  thwarts  to  bo  fixed  at  the  standard  depth 
below  the  capping-piece  or  gunwale,  and  the  securities  of  the 
thwart  knees  will  then  centre  the  rubber  and  gunwale. 

The  position  of  the  rising  ia  illustrated  in  Figs.  87  and  88, 

Thwarts. ^The  number  of  thwarts  in  a  pulling  boat  is  governed 
by  its  length,  and  in  accordance  with  the  following  particulars  : — 

LerlRth  of  Jift<boHt.  Niiniber  of  thwarts. 

18  ft.  and  under 4 

19,  20,  21.  22,  23  and  24  ft 5 

25,  26,  27  and  28  ft 6 

29  and  30  ft.     ...  ' 7 

In  order  to  keep  the  weight  of  persons  down  as  low  as  possible 
in  the  boat,  and  yet  not  too  low  to  make  it  difhcult  to  use  the 
oars,  the  following  depths  from  the  top  of  the  gimwale  to  the 
upper  surface  of  the  thwarts,  have  now  become  the  standard 

dimensions  to  which  most  boatbuilders  are  working,  viz.  : — 

DiiittLDGe  from  t< 
of  gunwale   to  U 
Length  of  bnot,  ol  thwart. 

26  ft.  to  30  ft.  (inclusive) 11    in. 

23  ft.  to  25  ft.        „  lOj  „ 

16  ft.  to  22  ft.        „  10    „ 

As  soon  as  the  rising  is  secured  and  the  keelson  placed  in 
position  the  thwarts  are  cut  to  length,  planed  both  sides,  and 
attached  tf)  the  rising.  The  scantlings  vary  from  9"XlJ'  in  a 
30-ft,  boat  to  8'  X 1^'  in  a  10-ft.  boat.  The  thwart  in  way  ol  the 
mast  hasp  is  increaserl  so  that  its  width  at  centre  is  not  less  than 
that  given  in  Table  XIV. 

The  materials  nsed  are  pitch  pine,  red  pine,  Baltic  redwood,  and 


IV; 


SHIPS'  BOATS 


'I'lulity  IS  ...ssftntial.    Urrh  Ls  „,™'™^*-V  Pulling  boaSf^  «***» 

is  U.0  narrow  to  allow  the  fnl  br  a^T.^,?"'*  "^^^^t^^H 
ninninx  inU,  8a,,  wood     H^Th^     '  ?''*'*  *«  b^  cu«  JS?****" 

wl.,t«  ,..,.«.  .„t  only  the  common  spnferf^H  1"°*  **»«  A^ricif 
avoKl..!  «..  .f.  ,ui..kly  Hphts  when 'e^pii^t'^^ **  »>«^2ty 

\Vh<m  the  iinHimiuirf<»M»....i.i.    r  .,      .  " 


r.wiiy  riii».i  up  iiiM)  spimterH.  "^^"^  weather  and 

When  th.!  lUiHiipported  lenirth  of  the  thw«rf 

a  HtandMon  or  p.Nar  is  fitt«l  at  the  centre.  1^2,^?^.®^*  '««t> 

th«  keelH.,n  an.|  neeurcl  t.,  the  underside "Tth^  ^K^*  *°P  ^^ 

:    >^>y>»/— ir  thwart,  not 


A££iSO/V 


Kiu.  75. 


two  screws 

!vf(>r  1(>  tiike  a  dovetail  clieck  out  of  th 
w  w.ll  Mv  vorfw..!  .ui)i)oi-t.    In  this  case 

" linylv. 

tlie  thwarts,  as  it 
ippoarance  t»  the  boat. 
T\\c  (Ml,m»s  of  tin*  Ihwiirts  in  any  raso  must  bo  rounded,  and  the 
o|HM'iition  o{  liejulin.u  iakos  very  liltle.  il  any,  extra  labour. 

With  referenee   \o  the  thwarts  of  a  "  square  stem  "  boat 
Iho  same  regard  should  be  paid  to  the  number  approved  to  be 


CONSTRUCTION   OF   CLA8S    Ia   OPEN   LIFE150ATS    157 

fitted  in  accordance  with  the  length  of  the  boat.  The  stern-sheets 
are  of  greater  length  than  the  usual  distance  between  the  thwarts, 
and  as  the  stern  seat  is  very  wide  to  allow  the  gangboard  to  be 
fitted  so  as  to  take  the  lifting-hook,  one  of  the  thwarts,  which 
is  included  in  the  regulation  number,  is  fitted  under  the  seat, 
with   the  usual  single  knee.     The  rising  is  fitted   from  stem 


-  -  .^^wiyALk 


ELEVATION - 


Fio.  70. — Mctliod  of  lilting  benchcM  in  u  "square-stem"  boat. 

apron  to  tniiLsom,  and  secured  at  every  timber.  The  gang- 
board  aft  is  fitted  in  a  similar  way  to  a  double-bowed  boat, 
the  upper  surface  being  kept  flush  with  the  stern  benches  by 
recessing  the  gangboard  over  the  thwart  and  securing  the  two 
together  witli  three  screw  bolts. 

In  a  Class  III.  boat,  where  it  is  not  necessary  to  fit  side 
seats  forward  of  the  second  th^\art  from  aft,  the  after  thwart 


158 


SHIPS'  BOATS 


is  uHually  let  into  the  imiv^  to  allow  for  the  fitting  of  the  after 
side  seats.  In  the  same  type  of  boat,  i.e.  an  ordinary  open 
pulling  boat  without  buoyancy  air-cases,  it  is  invariably  necessary 
to  fit  side  seats  to  provide  for  the  full  accommodation,  but  in 
a  "  jolly  "  boat,  which  does  not  form  part  of  the  life-saving 
equipment  of  a  vessel,  and  where  side  seats  are  not  fitted,  it  is 
either  necessary  to  increase  the  depth  of  the  knees  by  an  inch 
beyond  the  dimensions  shown  in  Table  XVIII.,  or  to  lift  the 
rising  one  incli. 

Fig.  76  illustrates  the  method  of  fitting  the  benches  and  after 
thwart  in  a  boat  with  a  square  stem. 

The  fitting  of  a  simple  vertical  tie  board  from  timber  to  timber, 
under  the  stern  benches,  is  more  ornamental  than  useful,  and 


PLAN 
Fig.  77. — Quaifcei  knees. 


U^^eft  ST/fAKK 


_^!KMCf 


B/AfOiAfC  SrWAiCF 


ELEVATION 


^^'iG.  78. — Quarter  badges. 


shoukl  be  avoided,  as  tlieie  Ls  little  or  no  supi)ort  given  to  the 
liftint'-hook. 

Quarter  knees  arc  iiltt.'d  lK*t\v<M.*ntli<^  gimwalrs  and  the  cross-piece 
attadicd  to  thti  tmnsoin  of  a  scjuaro-steni  boat.  The  arrangement 
is  illustiatcd  in  Kig.  77.  These  r(M[ui!e  very  careful  fitting  and 
must  be  cut  from  .selected  material  iirown  to  shape.  A  check  is 
taken  out  of  tlie  cross-[»ieee.  and  sometimes  also  from  the  gunwale, 
to  prevent  movement  and  to  inciease  tli(^  efiieieney  of  the  security. 
The  fastenings  are  of  stout  copper  rod  clenched  over  washers. 

The  stem  and  sternjmst  knees  are  fitted  to  strengthen  and 
protect  the  gunwale  and  upper  stiake,  but  unless  they  are  sub- 
stantially se(;ured  tlicy  only  become  useful  for  onia mentation. 

Gunwales. — Tlie  consensus  of  o])ini()n  among  boatbuilders  in 
regard  to  the  most  satisfactory  type  of  gunwale  leaves  no  doubt 


CONSTKUCTIt>N   OF  CLASS  U   OPEN  LIFEBOATS    169 

ill  the  minds  of  practical  men  that  the  "  box  "  form  is  the 
strongest  means  of  construction  for  all  types  of  boats. 
m       The  general  arrangement  of    such  a  gunwale  b  shown  in 
|jig.  79  A, 

It  will  be  noticed  that  the  timbers  are  carried  up  to  the  upper 
etlge  of  the  inner  gunwale  or  "  inwale,"  and  sheer  atrake. 

Before  timbering,  a  hard  wood  filling  piece  is  fitted  between  tlie 
sheer  strake  and  the  timbers,  fore  and  aft,  tapering  from  the  full 
thickness  at  the  lower  edge  to  lialf  the  thicloiess  of  the  binding 
strake  at  the  upper  edge.  By  tapering  this  filling  piece,  tlie 
fairness  of  form  is  maintained  in  the  boat.  The  effect  of  fitting 
a  filling  piece  of  parallel  section  has  the  tendency  to  throw  the 
gunwale  outboard,  which  gives  an  unsightly  appearance  to  the 
experienced  eye. 

The  inner  gunwale  is  usually  of  American  njck  elm,  varying 
from  2J  in.  to  3J  in.  moulded,  and  I  in.  sided,  and  is  fitted  in  one 
piece  from  stem  to  stempost  apron. 

The  upper  or  sheer  strake  is  not  less  in  thickness  than  ^  in. 
greater  than  the  planking.  The  breadth  is  an'anged  to  suit  the 
position  of  the  rubber  to  enable  the  throat  bolts  connecting  the 
thwart  knees  to  be  fitted  well  down  towards  the  side  benches. 
These  breadths  can  be  secured  by  reference  to  Table  XVIII.,  and 
should  be  continued  for  about  two-thirds  the  length  of  the  boat, 
gradually  tapering  towards  the  ends. 

The  inner  gunwale  and  sheer  strake  are  secured  to  every 
timber  by  copper  nails,  clenched  over  roovea,  and  placed  in  "  reel  " 
fashion. 

Care  should  be  taken  before  fitting  the  combinations  of  a 
■'  box  "  gunwale  to  see  that  all  faying  surfaces  and  heads  of 

[timbers  are  well  coated  with  white-lead  paint. 
SoUd  chocks  of  hard  wood  are  fitted  between  the  timbers  in  way 
of  the  thwart  knees,  breast-hooks,  and  crutches,  so  that  between 
Old  sheer  strake  and  inwale,  with  the  exception  of  these  chocks 
and  the  capping  piece,  there  is  left  an  open  space  which  ventilates 
the  gunwale. 

Those  chocks  should  be  of  selected  hard  wood,  free  from 
sapwodd,  and  well  secured  in  position.  Odd  pieces  of  material 
lying  about  the  boat-yard  ubould  be  discarded,  as  the  writer  has 
repeatedly  seen  evidence  ()f  timbers  rotting  at  their  heails  and 
tunning  down  to  the  bilge,  resulting  from  the  use  of  unsuitable 

Ctnatjirial,  and  there  was  no  alternative  but  to  rip  the  timbers  out, 
t  is  a  difficult  operation  in  boats  fitted  with  a  "box" 
ale,  and  one  which  does  the  planking  very  little  good. 


fi 

I 

I? 


SHIPS'  IJOATS 


aJterniillvE  method. 


CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS     16" 

Some  shipowners  prefer  the  open  "  box  "  gunwale,  i.e.  the 
omission  of  a  capping  piece.  Such  an  arrangement  has  the 
advantage  of  providing  a  good  hand-hold  for  gaining  access  into 
the  boat  from  the  water,  but  it  leaves  the  end  grain  of  the  timber 
heads  exposed  to  the  weather,  which  is  considered  a  disadvantage. 
In  good-class  wooden  saihng  vessels  all  exposed  end  grain  of 
btem  and  sternpost  heads,  bulwark  stanchions,  etc.,  are  covered 
with  sheet  lead. 

The  Ht-andard  practice  in  most  districts  is  to  fit  a  capping- piece 
about  I  in.  in  thickness  for  the  full  length  of  the  f^unwale,  and  well 
secured  to  tlie  inner  gunwale  and  sheer  strake  by  brass  screws. 
It  is  usually  fitted  in  two  lengths  in  large  pulling  boats,  and  if  the 
boatbuilder  steams  the  material  and  directly  bends  the  capping- 
piecc  into  position,  he  is  asking  for  trouble. 

In  most  yards  an  iron  mould  made  from  a  channel  bar  is  used 
for  bending  the  cappiug-pieces  after  steaming,  which  are  wedged 
in  this  position  for  a  day  or  two.  The  material  is  then  in  a  con- 
dition to  be  easily  worked,  and  proper  fastenings  can  be  inserted, 
otherwise,  if  steamed  and  worked  immediately,  the  builder 
is  in  such  a  desperate  hurry  to  get  the  capping  bent  at  the  ends, 
that  the  sti'css  on  the  material  is  too  gre-at,  and  if  it  does  not 
split  about  sLx  feet  from  the  ends  during  the  operation  of  bend- 
ing, it  eventually  may  do  so  after  six  weeks  of  exposure  to  the 
weather. 

Provided  the  inner  gunwale  and  the  sheer  strake  are  not 
touched  when  making  provision  for  the  insertion  of  the  crutches 
th  rough  thecappiug-piece  and  chocks  between  the  timbers,  it  seems 
ineceaeary  to  fit  cheek  pieces  to  the  "  box  "  gunwale  in  way  of  the 
crutches.  A  good  stout  plate  should  nevertheless  be  fitted  on  the 
face  of  the  capping-piece,  secured  with  four  stout  screws,  and  not 
I  the  usual  fitting,  about  2  in.  in  length  and  1^  in.  in  width,  which 
s  sometimes  fastened  with  two  French  nails, 

There  is  a  saving  of  material  in  working  tlie  "  box  "  giuiwale 
'  ic  comparison  with  the  "  soLd  "  gunwale,  and  when  the  employees 
|i  bwiome  accustomed  to  the  method  it  does  not  cost  more  than 
I  thirty  shillings  extra  in  a  20-ft.  lifeboat, 

An  alternative  method  of  forming  this  gunwale  is  sJmwn  in 
[Fig.  79  D,  which  the  writer  is  inclined  to  consider  as  a  "  mongrel  " 
I  type.  It  is  neither  the  solid  nor  the  box  form,  and  possesses  the 
I  disadvantage  of  leaving  the  upper  seams  exposed  to  the  weather, 
rand  eventually  water  may  find  its  way  between,  giving  an 
Vopportunity  for  the  timber  heads,  which  cannot  be  seen,  of 
Fitecoming  afiectcd  with  wet  rot. 


162  SHIPS'  BOATS 

This  method  is  not  recommended,  and  is  considered  inferior 
to  tlie  ordinal}'  and  "  open  "  type  of  "  box  "  gunwale. 

The  solid  gunwale  is  usually  fitted  in  pulling  boats  of  23  ft.  in 
length  and  below.  Fig.  79a  illustrates  the  details  of  this  combina- 
tion. The  timbers  form  no  comiection  with  the  gunwale.  They 
are  each  cut  short  to  allow  the  solid  gunwale  to  have  a  full  faying 
surface  on  the  sheer-strake. 

The  box  gunwale  is  more  resilient  than  the  solid  gunwale, 
and  transmits  the  stre-sses  through  the  timbers,  and  are  then 
equally  distributed  over  the  hull.  This  question  is  of  consider- 
able importance  where  boats  arc  launched  from  davits  situated  at  a 
considerable  height  from  the  water,  and  the  possibility  of  the  boat 
coming  in  violent  contact  with  the  ship's  side  during  the  operation 
of  lowering. 

Numerous  cases  have  occurred,  especially  when  the  thwart 
knees  were  not  secured  to  the  rubbers,  where  the  boats  have 
bumped  into  the  shell-plating  or  obstructions  on  the  side  of  the 
vessel,  and  the  solid  gimwale  having  no  contact  or  security  with 
the  timbers,  caused  the  upper  strake  to  split,  and  immediately  the 
gunwale  became  useless.  The  photograph  shown  in  Fig.  107  is  an 
illustration  of  what  actually  occurred  to  a  ship's  boat  when  being 
lowered  in  a  hurry  under  difficult  circumstances.  The  upper 
strake  split  in  the  manner  described,  and  the  gunwales  were, 
therefore,  of  little  use,  consequently  the  breast- hooks  were  broken 
and  the  whole  of  one  side  of  the  boat  came  away  from  the 
apron. 

It  is  a  waste  of  the  reader's  time  to  make  any  further  com- 
parison between  the  two  types  of  gunwales  under  review.  For 
any  type  of  open  pulling  boat  wiiich  forms  a  part  of  the  statutory 
equipment  of  a  vessel,  tiie  solid  gunwale  is  considered  a  dangerous 
fitting.  The  writer  may  have  been  unfortunate  in  his  experience. 
but  sufficient  has  been  seen  by  him  from  actual  results  to  make 
him  express  definite  views  on  the  subject. 

Solid  gim wales  are  fitted  in  one  piece,  care  being  taken  to 
obtain  tlie  correct  bevels  of  tlie  upper  strake,  to  allow  tlie  up|>er 
surface  of  the  gunwale  to  lie  in  a  horizontal  ])lane.  It  is  usual 
to  steajn  the  gunwale  and  clani[)  it  round  the  outside  of  the 
upper  strake  overnight,  in  readijiess  to  secure  in  place  tlie 
next  day. 

There  are  two  common  methods  of  ending  the  gunwales  at  the 
apron,  as  illustrated  in  Fi<is.  8<.)  and  81. 

The  first  method  siiows  the  end  of  the  gunwale  cut  off  with  a 
square  butt  and  checked  into  the  apron.    The  second  method 


I 


CONSTKUCTION    OF  CL.iSS  Ia  OPEN   LIFEBOATS    163 

provulea  for  the  enct  of  tlie  gunwale  to  be  cut  at  a  bevel  to  siiit  the 
back  of  the  apron.  There  is  little  to  choose  between  tha  two 
practices,  it  being  a  matter  of  individual  ta«to ;  but  that  shown 
at  Fig.  80  has  the  advantage,  that  wlieu  the  gunwale  receives  a 
bump,  the  effect  is  felt  on  the  apron  and  not  on  the  upper  strake, 
which  is  worth  considering  when  a  solid  gunwale  is  fitted, 

A  rowlock  was  originally  meant  to  be  a  row-lock,  and  cut  out 
of  the  upper  or  wash  strake  to  take  tlie  oar,  and  when  the  boat  was 
under  sail  the  rowlocks  were  filled  in  with  portable  j^pj^fs  and 
attached  to  the  boat  with  lanyards.  Rowlocks  are  not  often 
seen  in  pulling  boats  for  the  mercantile  service,  having  been 
replaced  by  criUdies,  aad  the  latter  are  now  generally  referred  to 
as  rowloclra. 

Provision  muat  be  made  for  the  loss  of  strength  in  the  aolid 


Fio.  80.  Kiu.  81. 

Piuiis  p(  eliding  suliJ  gunwulu  at  apron. 

gunwale,  in  way  of  the  crut«h  holes,  by  fitting  check  piexa  aboiiF 
10  in.  in  length  and  the  full  breadth  of  the  gunwale,  well  secured 
to  the  gunwale  and  upper  strake  by  copper  fastenings  clenched 
over  rooves  and  screws,  as  indicated  in  Fig.  82. 

The  depth  of  the  gimwale  la  not  sufficient  to  adequately 
support  the  shank  of  the  cruU-h,  which  makes  it  necessary  to  fit 
toe  cleatu,  hnniodiatcly  below  the  j;unwale,  as  shown  in  Fig.  82. 
Each  crutch  is  well  secured  by  a  chain  lanyard  to  the  boat. 

The  crutch  holes,  after  being  drilled,  are  burnt  out  with  a  hot 
round  bar  of  iron ;  this  prevents  the  wood  from  swelling  and 
allows  the  crutch  to  be  always  inserted  without  difficulty. 

The  material  of  the  solid  gunwale  may  be  of  American  elm, 
oak,  or  ash,  and  it  is  well  secured  with  at  least  four  clenched 
fastenings  between  each  pair  of  thwart  knees. 

An  improvement  can   be   made   on  the  solid  gunwale   by 


'^:j-  3..4^ 


-    _. 

•  ■   — *-*      ^ 

1 

•  •        ^ .      ^ 

w ; 

P    m 

*       • 

a   . 

^T'..' 

Tl-  :-.. 

w 

1.  .^^.  ; 

^L• 

'- .:  '.-.  : 

H .  w..  v^. 

i:n 

<r   r,   1 

•      « • 


^      • 


-        —  • 


-^  job.  bnt  ejM. 
-  *^t?  other.     I 


-  L-EI «  A-  "^s  _ 

—  ^    ^ 


_  -.  .y..-. /\i». .-. 


I CONSTEDCTION  OF   CLASS  Ia   OPEN  LTFEBOATS    165 


I 

^M  in  as  loog  leagths  as  the  breadth  of  ttie  material  will  allow.  It  ia 
^K  usual  to  secui'o  these  lengths  in  oue  breadth.  The  material  nmy 
^K'lie  of  pitch  pine,  yellow  pine,  teak,  or  red  pine,  f'ypress  quickly 
^H'dtiinks ;  Oregon  pine,  when  cut  into  small  scantlings  splits  and 
^r  opens  out  with  the  effect  of  warm  weather  unless  coated  with 
oil  immediately  after  workin;;.  Giood  resiilta  have  been  secure*! 
from  the  use  of  well-seasoned  Califoraiau  redwood,  hut  it  has 
the  disadvantage  of  ahowin^  everj-  impression  made  on  ita 
surface, 

Sufficient  experience  has  been  gained  with  the  use  of  white 
[  pine  and  Scotch  fir  during  the  period  of  the  European  war,  when 
I  timber  substrtutea  were  permissible,  to  recommend  that  these 
I  materiahi  are  unsuitable  for  the  purpose. 

The  common  method  recently  was  to  scarph — or  to  make  an 
I  attempt  at  scarphing— the  aide  seats  with  the  thwarts.  '  They 
1  are  now  fitted  in  continuous  lengths  above  the  thwarts  and  nm 
f'from  stem  to  sterapoat  apron, 

Tlie  "deck  "  ends  are  worked  from  the  first  thwart  to  the 
[  stem,  and  from  the  last  thwart  Ui  the  aternpoat.  The  centre  por- 
[  tion,  or  garu/boanl,  ia  made  of  the  same  material  and  scantlings 
I  as  the  thwarta.  A  common,  practice  is  to  slightly  check  it  over 
I  the  thwart  and  well  connect  it  to  a  ledge  chock  attached  to  the 
I  apron,  a  cross-piece  let  into  the  rising  and  bolt«d  to  the  thwart. 
I  Tliis  provides  a  rigid  coruiection  for  the  securities  of  the  lifting- 
[  hooks,  which  is  such  an  important  factor  with  a  lifeboat  filled 
rwith  a  crowd  of  passengers,  probably  numbering  fifty,  and 
|.«winging  in  mid-air  at  a  distance  of  thirty  feet  above  the 
I  water. 

Fig.  83  illustrates  the  method  of  fitting  the  gangboard  and 
"  deck  "  ends. 

Where  double  knees  are  fitted,  the  lower  palm  connecting  bolts 

I  afficiently  secure  the   side  benches  to  the  thwarts,  but  in  tlie 

Me  of  single  knees,  it  is  usual  to  arrange  the  butt«  of  the  side 

ftttenches  welt  clear  of   the  knees  and  bolt  the  former  to  the 

p  til  warts. 

To  provide  the  proper  seating, accommodation  for  tJie  total 
jQumbor  of  persons  assigned,  it  is  necessary  in  lifeboats  of  21  ft. 
jin  length  and  upwards,  to  fit  loicer  cross  seals.  These  are  made 
Iportable,  so  as  to  permit  wounded  persons  being  placed  at  the 
[bottom  of  the  boat,  if  necessary. 

Lower  scats  aerve  a  double   purpose  and  can  be  used  as 

(stretchers.     The  supports  are  made  out  of  English  elm  or  other 

niitable  hard  wood,  about  L  in,  to  1^  in.  in  thickness,  and  secured 


Boi 


INSTRUCTION   OF  CLASS  Ia   OPEN  LIFEBOATS     167 


Thwart  Knees. — The  thwart  kneea  are  now  usually  made  of 
wrought  iron,  owing  to  the  diificulty  of  securing  a  continuous 


1 


mm 


n.  85. — DooWe  wooden  kncps. 


Fin.  : 


{rnltu  kTioc 


iPPP'y  "^  wood  knees,  which  must  be  cut  from  material  j^own  to 
'lape. 

Larch  roota  make  good  knees  for  the  small  type  of  puUinj; 
lats.     English  elm  and  oak  kneea  must  be  securtMl  from  well- 
loned  wood,  giving  a  proper  crook,  and  sided  t4)  IJ  in.,  other- 
fee  Uicy  are  of  httle  use  and  (juickiy  split  from  the  cf^e 


168 


SmPS'  BOATS 


\ 


tJie  weather.  The  securitiea  must  be  of  ccipjier  or  galvanised  I 
iron  with  good  clenches  on  rooves  or  washers.  Wire  nails  are  not  I 
permitted  for  the  purpose  of  aecurity. 

Where  double  wooden  knees  are  fitted,  it  k  usual  fa>  secure  s 
pad  piece,  or  chock,  between  the  kneea,  as  illustrated  in  Fig,  85,  I 
tapering  off  to  nothing  at  the  toe  and  heel  of  each  knee.     This  ! 
method  adds  strength  and  support  to  the  knees,  and  is  certainly  I 
an  improvement  to  the  ordinary  type  of  wooden  knee. 

The  scantlings  of  knees  are  detaUed  in  Tables  XIV,  and  XVIII.  I 
The  usual  practice  b  to  fit  wrnught-iron  knees,     Jumped  or 


Fio,  87. — Half  seotioQ  of  Clasq  Ia  Ii 


welded  knees  are  not  permitted,  they  should  be  of  substantial   ' 
section  with  at  least  IJ  in.  of  material  at  the  throat.     The  iaatca-  ] 
ings  are  arranged  so  an  to  obtain  the  greatest  amomit  of  aecurity  ] 
in  co-operation  with  the  combinations  in  way  of  the  gunwale  ;  nut 
and  screw  bolts  are  usually  fitted  for  the  purpose,  the  upright  arm  J 
having  one  security  through  the  centre  of  the  gunwale,  timber,  | 
or  chock,  and  upper  strake,  and  another  through  the  hardwood  \ 
chock,  binding  atrake,  and  rubber,  the  nuts  being  on  the  upper 
arm  of  the  iron  kniee  with  the  bolts  lightly  clenclied  over  the 
nuts.     The  securities  in  the  horizontal  arm  attached  to  the  side  ] 
benches  or  thwarts  are  generally  three  in  number,  the  centre  one  1 


CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS    169 

being  a  stout  screw,  aud  the  other  two.  ordinary  nut  and  screw 
bi)Ita  ;  but  iu  this  case  the  nuts  are  placed  on  the  undereide  of  the 
thwart  and  sci-ewed  up  on  atout  washers,  with  the  pointe  of  the 
bolts  8li;fhtly  clenched  over  the  nuts.  If  the  nut«  were  secured 
on  the  horizontal  arm  of  the  knee,  they  would  be  a  source  of 
danger  to  men  runninf?  alonjr  the  side  benches,  and  tend  to  throw 
them  overboard.     It  ia  iiaual  to  lit  a  protectinj;  strip  of  wood,  or 


»I5« 

1 

i 

i  .,;.,».„„, 

t„ 

,^'l{     .u..-iV..„    If            ' 

rl    -Ui"!':'  1 

r' 

Fio.8 


— Methiicl  of  lillirif!  thu-nrt  knccri  mid  sitta  bencliea. 


liataoM,  attached  to  the  thwart,  to  i^eep  the  buoyancy  air-cases  off 
the  nuta. 

Fig.  88  shows  the  details  of  the  securities  for  iron  knees  of  the 
ordinary  pattern. 

Table  XVIII.  has  been  drawn  up  to  simplify  the  work  of  the 
boatbuilder  and  smith  ;  if  the  various  dimensions  are  adhered  to, 
the  combinations  in  way  of  the  ^iimwale  will  be  so  placed  as  to 
always  allow  the  securities  to  coincide  witJi  the  holes  already 
drilled  by  the  smith  in  the  thwart  kniee.  It  often  prevents  the 
bolts  being  inserted  at  a  great  bevel,  or  missing  the  rubber 
altogether,  and  necessitating  the  bolt  being  secured  to  the  binding 
or  upper  strake. 

Single  knees  are  permissible  in  boats  of  24  ft.  in  length  and 
under,  but  it  is  the  general  impression  amon^  boatbuildera  and 
otherH  that  this  is  a  very  prominent  weakness  in  the  present 


♦     .  ^*v* 


"■^       >■.   '..'.T  '        ■.  ^=?^-*   I 


-      'f 

1 . 


"r 


. '    :"::_r  z    >.-e 


■  ,  •    '  / "    ■.      It...... 


:>     i:.r:->o  are 
-  :>:v  -:ii-::o  or 


CONSTRUCTION  OF  CLASS  Ia  OPEN  UFEBOATS    171 

double,  so  as  to  be  of  some  substantial  support  to  the  com- 
binations. 

WKen  single  knees  are  fitted  the  scantlings  are  increased. 

A  concession  has  recently  been  granted  to  fit  knees  of  convex 


iron,  f  in.  in  thickness,  in  boats  of  24  ft.  in  length  and  under.  No 
reason  is  seen  for  lowering  the  standard  in  this  respect.  This 
practice  was  never  seen  by  the  author  in  yards  of  good  boat- 


I    '^ 

«'f'     I  I       ; 

1  (o/   \ol  I 


SECTION  PLAN 

Fro.  90.— DotaiU  of  Hornby's  patent  knee.    (No.  10,704.) 

builders,  but  it  naturally  follows  that  the  competing  finns  will 
be  guided  by  the  minimum  standard. 

All  iron  thwart  knees  must  be  galvanised. 

Id  lieu  of  the  double  iron  knees,  a  special  type  of  wrought- 
iion  single  knee  liaving  double  palms,  is  sometimes  fitted.    The 


172  SHIPS'  BOATS 

upper  or  vertical  arm  is  hooked  over  and  well  fitted  to  the  gunwale 
and  sheer  strake.  The  horizontal  arm  has  double  palms  which 
are  securiMl  to  tlio  thwart.  An  illustration  of  the  arrangement 
is  shown  in  Fiir.  ^^<). 

To  provi<lo  ef!i(i(»nt  soturitios  for  the  reasons  previously  given, 
these  double  palm  knees  should  be  so  designed  as  to  allow  one 
of  the  bolts  to  pass  through  the  rubber.  There  is  certainly  a 
saving  of  weight  with  this  type  of  knee,  but  not  very  much 
advantage  is  gained  in  cost.  The  greatest  care  has  to  be  exercised 
in  making  each  knee  fit  at  the  gunwale  at  the  particular  thwart, 
to  prevent  the  nece-ssity  of  fitting  filling  pieces. 

A  very  elHciont  type  of  single  knee  having  double  palms,  is 
that  which  has  boon  patented  by  Mr.  Hornby,  of  Seacombe,  near 

Liverpool,  the  details  of 
..^^s^jr^A^^  V    .  which  are  inven  in  Fig.  90. 

A  il^    ^  .  V  -  -r^^>^v         The  dmerence  between 
/^f''^         ''  •^6£^s  this  method   of   forming 

''^\/  the  knee  and  the  approved 

z"^^-     -'^         ^     .^   ,  ccmvex    pattern   is    verv 

^^^'^^^     \  -^  marked. 

^     ^  ij'^  ^  Breasthooks  and  Floors. 

surr        J;  -?*  — Ref (jrence  has  already 

,,.  r.,/>/>//yd^    <i     >'^  \^^^^  nx^A^  to  the  neces- 

sity of  providing  efficient 
combinations  at  the  ends 
r^''  of    boats    to    meet    the 

Fkj.  01.-  -Plan  of  upprr  broaMlKM.k.  heavy  stresses  which  come 

upon  them  from  the  lift- 
ing-hooks, (»tc.  Stout  })reastlio()ks  must  be  iitted  at  the  aprons 
and  gunwale  eiuis ;  the  securities  of  which  are  similar  to  those 
of  the  tliwart  knees,  having  a  throat  bolt  which  passes  through 
to  the  face  of  tlie  stem  or  sternpost.     (Sec  Fig.  91.) 

When  made  of  wrought  iron,  the  breasthook  should  be  of 
substantial  thickness  and  not  loss  than  \\  in.  at  the  throat. 
The  use  of  cope  inm  shoukl  be  entirely  avoided. 

Wooden  breasthooks  are  cut  from  material  grown  to  shape. 
Lifeboats  over  21  ft.  in  length  must  be  fitted  with  an  upper 
and  a  lower  breasthook,  both  at  the  stem  and  the  sternpost. 

\Vh(»n  the  lif(»boats  are  lifted  from  near  the  ends,  as  with  the 
Welin  davits,  a  lower  breasthook,  or  deep  floor,  is  essential  in 
all  boats,  irrespective  of  length. 

This  lower  breasthook  is  fitted  midway  between  the  deadwood 
and   apron  scarph   and  the  upper   breasthook,  and  is   usually 


C"JX=»'''V. 


(  nNsTIM"(  TlOX    OF    (LASS    Ia    oPKN    LIKKi;().\Ts      i 


I  • » 


!ii(«ii  {>Miatr([  witli  till'  emliiiLi  <>t  tlic  l)il;jr  si  liiinci-.  (  Jiuc'k.s  liriiiu 
lit  ted  between  tlie  timbers  iii  wav  of  tlic  iron  breasthook.  (Sec 
Fi-.  92.) 

The  writer  lias  a  preference  for  a  good  stout  wooden  breasthook 
with  a  throat  bolt  well  secured  to  the  face  of  the  stem  or  stempost, 
and  having  arms  of  sufficient  length  to  allow  for  through  fasten- 
ings at  two  of  the  timbers,  on  each  side  of  the  boat.  In  this 
case  the  breasthook  is  checked  over  the  timbers  and  just  touches, 
but  doe>  not  unduly  bear  hard  on  the  planking,  the  full  bearing 
being  taken  by  the  timbers.  Care  must  be  taken  to  fit  wedge- 
shaped  liners,  or  filling  pieces,  behind  the  timbers  in  way  of  the 
breasthook  to  prevent  the  planks  being  drawn  at  their  centre 
and  splitting. 

The  fitting  ol  floors  at  the  ends  of  a  boat  depends  on  the  type 


3/lC£  Sr^fdVG£-4f 


//ra/v  3^£'AsrHOO^ 


SreM 


S^£ASrMOOA 


Fio.  92. —  Plan  of  iron  lower  breofithook. 


r/ArB£A 


Fig.  93. — Plan  of  wooden  lower 
breastliook. 


and  position  of  the  lifting-hooks.  Provided  the  timbers  have  been 
checked  into  the  deadwood,  it  is  usually  only  necessary  to  fit 
one  deep  floor  at  each  end  of  the  boat,  near  the  lifting-hooks, 
checked  over  the  keelson  and  incorporated  with  the  timbers. 

When  the  timbei*s  are  not  checkeil  into  the  deadwood  some 
specifications  insist  on  floors  being  fitted  at  every  third  timber 
which  does  not  cross  the  deadwood  or  hog. 

The  working  conditions  of  the  smaller  type  of  coasting 
steamer,  paiticularly  in  regard  to  trawlera,  make  it  necessary 
for  their  boats  to  be  constructed  on  lines  which  are  suitable  to  their 
requirement«,  and  it  is  usual  to  iit  a  heavier  form  of  hog  and 
dispense  with  the  keelsoji,  as  the  latter  would  interfere  with  the 
usefulness  of  the  boat.  Good  stout  floors  are  fitted  at  the  ends,  as 
the  boats  are  usually  lifted  on  board  with  a  wire  sling. 

Rubbers  and  Anti- fouling  Arrangements. — Rubbers  are  usually 


174  SHIPS'  BOATS 

made  from  ^Vmcricau  elm  or  oak,  in  half-round  or  pear-shaped 
section,  and  extend  in  one  piece  for  the  full  length  of  the  boat, 
being  secured  to  alternate  timbers  with  copper  nails  clenched 
over  rooves. 

The  feature  of  these  rubbers  is  not  only  to  form  a  protection 
to  the  gimwale,  but  an  excellent  longitudinal  stiffener  is  provided 
when  associated  with  the  thwart  knee  securities. 

It  is  considered  that  it  would  be  an  advantage  to  the  boat  to 
increase  the  scantlings  of  the  binding  strake,  owing  to  the  number 
of  heavy  fastenings  which  pass  through  it  when  securing  the 
life-line  rings  and  rubbers. 

Where  boats  are  not  fitted  with  a  rope  fender  or  outside  cork 
buoyancy,  the  lower  edges  of  the  planks  of  clinker-built  boats, 
from  the  binding  strake  down  to  the  turn  of  the  bilge  (usually 
about  the  fifth  plank  below),  are  fitted  with  tapered  filling  pieces, 
for  a  distance  amidships,  equal  to  one-half  the  length  of  the 
boat.  Vertical  rubbing  pieces  may  be  fitted  if  desired,  but 
the  usual  practice  is  to  fit  the  horizontal  strips  and  secured  to 
the  timbers. 

The  purpose  of  these  filling  pieces  is  to  protect  the  plank  edges 
and  landings  from  damage,  should  the  boat  come  into  contact 
with  the  ship's  side  when  being  lowered  overboard. 

Care  should  be  exercised  in  fitting  rubbing  strips  to  give 
them  a  neat  rounded  section  in  order  to  preserve  a  finished 
appearance  on  the  plank  edges. 

Bilge  rails  are  not  required  to  be  fitted  by  the  standard 
regulations  issued  by  the  Board  of  Trade,  but  they  provide  an 
excellent  handlioid  for  persons  stniggling  in  the  water,  and  should 
the  lifeboat  be  capsizetl,  they  become  a  ready  means  of  assistance. 
Tlie  details  of  fitting  the  rail  below  the  turn  of  the  bi}ge  is  shown 
iu  Figs.  9-1  li  and  o. 

The  position  of  the  rail  at  the  bilge  should  be  such  as  not  to 
foul  the  ship's  side  when  tlie  boat  is  lowered. 

it  is  secured  t^)  the  planking  and  alternate  timbers  by  stout 
screws,  care  being  exercis(*d  to  prevent  the  fastenings  from 
[uercing  the  full  thickness  of  timber. 

The  Peninsular  and  Oriental  Steam  Navigation  Co.,  Ltd.,  in 
their  double-skin  lifeboats,  have  an  upiMir  Juuid-rail,  or  jackstay, 
fitted  at  the  gunwale.  The  arrangement  is  illustrated  in  Figs.  79  c 
and  Dl  a.  The  life-lines  are  secured  to  the  gunwale  rail.  The 
relative  positions,  of  the  bilge  rail,  life-lines,  and  gunwale  rail, 
provide  every  facility  for  persons  obtaining  access  into  the  boat 
from  the  water.    This  has  been  a  standard  practice  with  Messrs. 


CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS    175 

C^ainl  and  Co.  for  many  years,  aad  ia  a  considerable  improvement 
«u  the  arrange  nieiita  usually  fitted  in  ships'  boatA. 

An  efficient  form  of  protection  to  the  transom  and  plank 
codings  in  a  "  square  stem  "  boat  is  given  by  the  fitting  of 


.PiAJVK/fVC 


m 


J)  ^  '■ 


S  /?A/*-       ^^ 


A,  iilnn  of  jiirkKtay  or  uuawiilg  rail. 

».  Irian  uf<<URcr*ll. 

v.  Mti-tluii  n[  lilbn  rail. 

I>,  metliiHl  ol  llttlDK  lUg-Une  rlufl*. 


quarter  baAjes,  illustrated  at  Fig.  78.  They  are  made  of  hard- 
wood and  secured  to  the  fashion-piece,  gunwale,  planking,  and 
rubber. 

The  necessity  for  the  provision  of  rope  fenders  in  all  lifeboats 


SHIPS'  BOATS 


is  obvious  to  persons  wlio  have  hod  any  piactjcal  oxpeiieoce  io 
the  operation  o(  launching  I>oata  under  difficult  circumstances. 


mpJiL  scfCM  n 


iiAW 

SECTION 

Vm.  ys.— Coir  rci|H'  fi-uiicr  filtvd  to  moiliiicil  ClsM  Ua  lifeboat. 

Hand  fcndei'B  are  cuii^iclcred  very  objectionable,  and  in  all 
f<robabi))ty  would  be  found  itiisHing  when  required. 

A  7-in.  rope  fender 

_P  would  certainly  limit 

the  riak  of  damage  to 

>«J^£  the  hull  of  a  boat  if 

ellieiently  secured  im- 

'         '    ,.■  ,  ;.f^*„      mediately  under   the 

\       .'  ■  '■vi  '■(■ysj-zr  rubber. 

^—     j  These      fenders 

^  should  be  j-ieldiuf^  and 

^    ~  resilient,  and  if  coir  is 

used  it  should  coQsi£t 

of  long  strands  as  a 

rule,  uulaid,  but 

marled  to  tiie  necee* 

Mjiry  diameter,  and  iu 

no  case  should  the  fen- 

■  der  be  less  than  4  in. 

l''io.  ii(i.—  Jfojit  ItiiUiT  u>  iiii.iur  Ixiiit.  <-'oir  rope  is  made 

from  the  libres  of  the 

oi-dinuiy  hemp  rope,  and 


w 


cocoamit  tice,  is  much  lij^htiT  than  the 
about  equal  in  Mlu'iii;th. 

Fiji.  "■>  shows  lln'  iiieOidd  of  littiny  coir  rope  fenders  to  the 
iiLoditied  Class  Ua  lifeboats. 


CONSTRUCTION   OF  CLASS  1a  OPEN  LIFEBOATS     177 

Another  methoil  sometinieB  adopted  as  a  means  of  pnitectint; 
motor  boats  is  illustrated  by  Fit;,  ^*h  ^^*^  consists  of  a  number 
of  strands  of  rope  made  up  to  tlie  required  diameter,  secured  to 
tlie  timbers  by  strong  wire. 

Padding  Rentiers  are  made  up  from  old  rope,  unlaid  and  served 
with  apunyam  to  about  6  in.  in  diameter,  covered  with  canvas 
and  painted,  or  with  rope  mattinsi.  Fig.  97  ilhistrates  the 
method  of  securing  these  fenders.  The  pudding's  and  the  life- 
lines are  attached  to  a  coir  rope  from  4  to  7  in.  The  mcoaurenient 
of  the  rope  is  taken  around  its  circumference. 

It  is  easential  that  the  loops  of  the  life-lines  should  be  kept 
parallel  to  the  L.W.L. 

There  is  a  diversity  of  opinion  as  to  the  relative  value  of  the 


^L    tlie 
^B    euffi 


Fio.  »7.— Puiiiling  (endprs  and  life-li 


pudding  fender  as  compared  with  the  ordinary  coir  rope.  WTien 
the  boat  conies  into  violent  contact  with  the  ship's  side  the 
stress  is  partially  taken  by  the  pndding  fender,  but  transmitted 
to  one  particular  portion  of  the  gunwale  combination,  whereas 
it  is  considered  that  with  a  large  continuous  rope  fender,  the 
stresses  would  be  distributed  over  a  wider  area  and  local  damage 
would  be  avoided. 

The  writer's  exjierience  is  that  the  puddings  very  quickly 
get  damaged  and  need  constant  attention  and  repairs. 

When  lifeboats  are  lifted  at  the  ends  by  the  Weiiii  quadrant 
type  of  davit  bracket,  also  the  Martin  or  McEkchnie  patterns,  it  is 
necessary  to  substitute  two  thicknesses  of  reinforced  rope,  in  lieu  of 
tlie  pudding  fenders  at  the  stem  and  atempost,  tu  allow  for 
eufficient  clearance  at  the  davit  frame. 


178 


SHIPS'  BOATS 


The  Board  of  Trado  have  recently  isaued  a  circular,  No.  1606, 
reeomniendinf;  that  where  {langeroiis  fittings  are  already  fitt«d 
(in  pxistinf;  nliips  below  the  boat  positions,  action  niiiBt  be  taken 
U>  modify  tlie.-c  pn)jcctiona,  or  fit  special  fore  and  aft  coir  fenden 
not  lesx  tliaii  4  in.  in  tliameter.  and  secured  under  the  nibben 
of  the  boatn.  In  addition,  three  vertical  rubbcrB  are  to  be  fitted 
aroi<lRliips  mode  up  of  homp  rope,  tapering  from  3  to  12  in.  in 
(-ireiinifen-Ji(-e,  the  thickest  portion  of  the  rubber  protecting  the 
}iil}>e  of  the  boat  adjacent  to  the  ship's  side.  These  midship 
rulibors  are  to  be  weoured  from  gunwale  to  giinwale. 

Anipbt  pntt^ction  is  thiut  provided  when  the  boat  is  being 
h)W<Te(I  from  a  vessel  having  an  adverse  list,  and  to  meet  the 
contmgencv  when  it  is  thrown  against  the  ship's  side  by  a 
heavy  sea  when  afloat. 

Tank  CleadlnE. — Tlie  front  casing  which  encloses  the  buoyancy 
air-tanks  is  worked  in  short  gates  between  the  thwarts,  08  illus- 


Vi' 


ELEVATION 
-Mctlind  of  littinj;  tiink  ck'niling. 


trated  in  Vi}".  OH,  and  made  up  of  narrow  "  vced  "  pine  of  J  in. 
to  ^  in,  tliick.  ti<Hid  Mt<mt  olan)]Uj  arc  fitted  to  the  portable 
p()rti(ins  of  tlic  casing  to  enable  tJie  toiiks  to  be  periodically 
inspected  witJioiit  damaging  the  cleatiing. 

.Solid  supports  at  least  J  in.  in  thickneea  are  fitted  under  the 
thwarts,  and  setmrcd  in  place  in  such  a  manner  as  to  be  of  some 
substantial  help  to  relieve  the  weight  on  the  thwart. 

The  cleadiiig  is  held  in  |>ositiou  by  an  inner  and  an  outer  strip 
of  wood  naming  fore  and  aft  at  its  lower  edge.  Some  firms 
utilise  the  bilge  stringer  for  this  purpose.  Consequently,  the 
stringer  is  fitted  in  such  a  position  as  to  give  the  minimum 
amount  of  support  to  the  bilge,  A  portable  securing  strip, 
made  of  teak  or  other  suitttbie  hard  wood,  and  rounded  at 


PeONSTRUCTION   OF  CLASS  Ia  OPEN  YlFEBOATS    179 

I  its  upper  edge,  elieck«l  at  tlie  thwarts  and  butted  at  their  cpntres, 
1  hol<b  the  upper  edge  of  the  cleadinft  securely  in  position,  gives 
I  a  neat  finish  to  the  boat,  and  provides  the  quickest  means  fnr 
I  removing  the  Imoyancy  air-tanks  without  dama|j;ing  the  cleading, 
[  The  cleadinK  front  is  kept  flush  with  the  side  benches  by  the 
I  fitting  of  an  inner  upper  ledge.  The  portable  securing  strip  la 
\  attached  to  tlie  side  benches  with  button-beaded  brass  screws. 

To  provide  for  easy  withdrawal  between  the  solid  siipporte 
L  under  the  tbwarU,  buoyancy  air-tanks  should  not  be  more  than 
I  3  ft.  G  in.  in  length. 

Attention  must  be  paid  to  the  mctfiod  of  fitting  the  cleading 
I  in  the  stern  and  head  sheets,  in  its  relation  to  tbe  floor-bfiards,  to 
I   enable  the  former  to  be  easily  removed  without  diffictUtj-. 

The  whole  of  the  arrangements  8h(iuld  be  of  a  substantial 
character,  to  enable  the  buoyancy  taniis  t«  be  inspected  and  the 
planking  behind  periodically  painted. 

Some  form  of  protection  is  given  to  the  air-casea  from  the 
copper  clenched  naila  in  the  timbers  by  securing  their  wooden 
I  strips  to  the  face  of  the  timbers  as  shown  in  Fig.  89. 

Rudder  and  Steering  Arraagements.^lt  would  almost  appear 
I  auperfiuoiis  to  state  that  the  rudder  should  be  of  ample  strength 
\  and  siutable  in  •^orm,  but  esperionce  proves  the  necessity  of 
I  inserting  full  particulars  in  the  ai>ecification9. 

The  material  must  be  of  a  tenacious  character,  not  easily  split, 
pith  a  thickness  varying  from  1  in.  to  1}  in.  English  elm  serves 
the  purpose  as  well  aa  any  wood.  The  rudder  ia  worked  in  one 
piece,  the  lower  edge  being  protected  with  a  toe  piece  and  secured 
by  spikes.  The  upper  portion  is  strengthened  by  clieek  pieces,  at 
I  least  }  in.  in  thicloieas,  carrie<l  down  below  the  upper  pintle,  and 
I  worked  with  an  oval  section. 

Fig.  99  shows  the  rudder  attached  to  a  2fi-ft.  lifeboat  of 
IClass  Ia,  and  Fig.  100  illustrates  the  type  of  nidder  fitted  to  an 
|18-ft.  dinghy. 

The  cheek  pieces  should  be  well  secured  to  the  nidder  by 
^elenched  copper  fastenings. 

The  arms  to  the  lower  jntitle  should  be  fitted  to  within  an  inch 
'  of  the  full^breadth  of  the  nidder,  which  prevents  the  latterfrom 
splitting. 

The  shape  of  the  rudder  should  give  a  pleasing  appearance, 
and  the  full  width  carried  down  to  the  upper  edge  of  tJie  keel. 

I  The  upper  ancl  lower  braces  are  secured  to  the  stempost  by 
denched  rivets,  not  simply  by  a  French  nail  clenched  over  a 
Toove  fitt«d  in  the  countersunk  hole.     The  securities  of  tlie  pintle 


I' 

t 
p 

■ 

C 

: 


SHIPS'  BOATS 


I 


Fiu.  loo.- — Kudiii^r  iilliH-liril  I  uii|iiiiin-atini  dinghy 


arms  to  *he  ruddw  are  1 
also  of  lieavy  copper 
nails  and  well  clenched. 
Oudgeons,  which 
are  driven  iat*i  the 
atempoat,  depending 
for  their  security  on 
a  rough  or  jagped 
edge,  should  never  be 
allowed ;  and  in  sqiiarc- 
Btemed  boats,  where 
the  upper  security  must 
be  attached  to  the 
transom,  the  spijjot  of 
the  gudgeon  should  be 
long  enough  to  paaa 
through  the-etempost 
and  be  clenched  over 
a  washer  on  the  face 
of  tlie  latter  or  secured  ] 
with  nut  and  screw. 

TUe  common  prac-  ] 
tice   is  to  fit  rudders  ] 
with  pintles  and  braces  | 
as  de-acribed,  but  this 
arrangement    is    con- 
sidered to  be  an  infe- 
rior one,  and  makes  the 
operation  of   shipping 
a  heavy  rudder  one  of 
f;reat     difficulty     and  | 
danger. 

The  best  method  is  ] 
by  fitting  a  guide  bat  1 
on  the  sternpost,  andl 
with  a  claw  type  ofi 
jiiTitlo  well  secured  to'l 
till'  rudJer,  the  details! 
of  which  are  shown  inj 
Fig.  101.  Allgood-cla 
pulling  boats  and  mo- 
tor boats  are  Ettedwithl 
rudders  of  this  design. 


—  ELEVATION  — 


C//£-£/C  P/£rC£ 


^mmm^^ 


f^oDoea 


2^ 


t 


~  PLAN  AT  UPPER  ARM  - 


S/fAC£ 


LOW£^  A/fAf 


"  PLAN  AT  LOWER ARM  - 
Fio.  101. — Details  of  rudder  hinged  on  guide  rod. 


—  ELEVATION   AT  HEEL  — 
Jl'io.  iOa.^Dut.iilii  u£  ruddLT.     AlU-mutivi;  method  of  hinjpug. 


CONSTKUCTiON  OF  CLASS   U  OPEN  LIFEBOATS    183 

Where  rudders  are  of  siic^h  a  size  and  weight  as  to  make  them 
somewhat  difficult  to  ship,  an  cxcollent  practice  exists  among 
some  boatliuildcrs  of  con8tructiii<;  the  rudder  an  illustrated  in 
Fig.  HI2,  The  iron  rod,  in  this  caac,  ia  attaclied  to  the  rudder, 
and  not  to  the  aterniwat,  by  well-secured  amis.  At  the  head  o£ 
the  sternpost.ia  a  hinf^od  socket,  into  which  ia  sliipped  the  iron 
rod  of  the  rudder,  when  the  latter  is  in  the  horizontal  position. 
The  rudder  ia  then  attached  to  the  boat.  The  socket  is  hinged 
over  into  a  vertical  position,  which  allows  the  rod  to  slide  into  a 
grooved  guide  bar  attached  to  the  etenipoat.  Tlie  head  of  the 
rudder  is  arranged  to  take  a  tiller  in  addition  tai  a  yoke  and  tines. 

Yoke  huM  arc  unsuitable  when  iwiliug  a  boat,  and  the  general 
practice  is  to  ht  a  tiller.  Both  the  rudder  and  tiller  must  be 
secured  to  the  boat  by  lanyards,  eyebolts  being  fastened  to  the 
gangboard  for  the  purpose. 

When  a  heavy  sea  ia  running  it  becomes  a  difficult  operation 
to  control  a  boat  with  a  rudder.  With  this  in  view,  all  boata 
must  carry  a  steerinij  oar. 

The  simplest,  most  efficient,  and  yet  one  of  the  oldest  methods 
of  holding  the  steering  oar,  ia  by  fitting  a  wire  ffrommct,  served 
over  with  marlin  stuff  or  spun  yarn.  This  is  seized  behind  the 
ring  bolt  and  a  good  security  made.  The  length  of  the  grommet 
should  be  such  that  the  blade  of  the  eteerin^  oar  can  easily  L 
inserted  and  the  oar  iised  on  cither  side  of  the  sternpost. 

To  protect  the  capping  of  the  gunwale,  rubbing  pieces  are 
fitted  on  each  aide  of  the  atcrupost  for  about  15  in.  in  length,  a 
secured  to  the  gunwale  by  screws.  The  thickness  ia  about 
I  in.,  and  the  upper  surface  well  roiuided  into  the  sternpost  knees. 
It  is  much  easier  to  repair  a  rubbing  piece,  than  a  gunwale  which 
has  become  damaged  through  the  continual  use  and  chating  of 
the  steering  oar,  An  illustration  of  the  arrangement  is  shown  ii 
Fig.  103. 

In  a  "  square  stern  "  boat  a  rowlock  is  usually  cut  in  the 
transom  for  the  purpose  of  sculUng,  The  steering  grommet,  in 
this  case,  is  seized  behind  the  ring  bolt  in  the  usual  manner,  and 
with  the  rowlock  combined,  provides  an  efficient  arrangement 
for  working  the  steering  oar. 

Several  other  methods  are  in  operation  for  taking  the  steering 
oar,  by  fitting  suitable  crutches,  as  shown  in  Figs.  104  and  105. 
The  most  expensive,  but  the  most  reliable,  is  the  method  illus- 
trated m  Fig.  lOj.  A  chock  is  fitted  on  each  (juarter,  about  18  in. 
from  tho  sternpost,  an<l  bolted  through  the  sheer  strake  and 
gunwale,  through  which  is  pierced  the  hole  to  take  tho  crutch. 


SHIPS'  BOATS 


In  the  rnitch  i)Iat«  and  fiunwale  a  keyway  is  cut  to  allow  the 
fciithor  piece,  attached  to  the  shank  of  the  crutch,  to  enter  in  a 


fore-and-aft  ilircction.  WJien  the  crutch  is  turned  round  to  its 
correct  [Hwitioii  for  tukiiijr  tlic  steeriDjj;  oar,  the  key,  or  feather 
piwe,  comes  into  contact  with  the  lower  edge  of  the  gunwale 
and  prevoiits  the  cnitch  from  lifting.  The  heel  of  the  crutch 
should  also  be  swinetl  by  a  chain  lanyard  to  the  boat. 


Wien  tiic  steei'inj;  oar  in  inserted  in  tlie  crutch,  the  hiti;;ed  top 
ia  sei'iired  in  i)o8ition  by  a  yiu  attaclied  to  a  chain.     The  height 


I  CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS     185 

I  of  the  cnitcb  is  an-anj^ed  to  allow  the  steering  oar  to  oleai  the 
^  8t«rnpoat  head. 

In  any  case,  tlie  cratches  should  be  luade  portable,  otherwise 
I  they  become  a  source  of  danger  to  the  boat  in  fouling  ropea  and 
1  wreckage. 

Stem  and  5k^  Bands. — The  heads  of  stem  and  sternpnst  must 

I  be  shaped  so  as  to  facilitate  clearance  should  the  boat  be  fouled 

*  by  a  rope  or  wreckafje,  and  they  are  trimmed  so  as  not  to  projett 

above  the  gunwale  more  than  ia  necessary.     Some  firms  cut  them 

flush  with  the  gimwale.     The  practice  saves  a  little  labour,  but 

spoils   the   appearance  of   the   boat   and   leaves   too   sharp  a 

projection  on  the  stem.     The  stem  band  is  made  of  wrought 

iron,  and  extends  from  the  apron,  over  the  stem  head,  to  about 

2  ft.  abaft  the  stem  and  keel  scarph.     It  is  fitted  to  the  actual 

width  of  the  stem  bearding  and  follows  the  run  of  the  fullness 

,  down  to  the  heel  of  the  stom,  so  that  the  band  becomes  of  some 

I  real  value  to  prote'^t  and  strengthen  the  keel  and  stem  scarph. 

The  practice  of  fitting  cope  iron  to  serve  the  purpose  of  a 
V  stem  band  is  of  little  value  for  strength  or  ornamentntion. 

Recently  an  alternative  arrangement  has  been  allowed  whereby 

■  convex  iron  may  be  used,  provided  the  breadth  is  not  less  than 

two-thirds  the  full  siding  of  the  stem  ;   a  very  ugly  stem  will  be 

the  result,  and  few  boatbuJlders  of  repute  will  work  to  such  a 

method. 

The  ske^  hand  extends  from  the  lower  rudder  brace  to  two  feet 
I  forward  of  the  keel  and  stempost  scarph, 

A  standard  mould  or  thin  batten  should  be  supplied  to  the 
smith,   giving  the  correct  shape  of  atom   band  required,  and 
indicating   thereon   the  correct   praition  of  the  securities,  so  as 
to  avoid  the  fastenings  of  stom  or  ske^  bands  fouling  those 
.  securing  the  stem  and  stenipost  to  the  deadwoods  and  aprons. 
Figs.  43  and  44  show  the  bands  fitted  in  position. 
LUe  or  Grab  Lines. — Where  upper  hand-rails  are  fitted  at  the 
^  gunwale,  the  life-lines  are  secured  through  the  rail  as  shown  in 
Fig.  94  A. 

The  usual  practice  is  to  supply  the  rings  attached  to  staples, 
which  are  secured  through  the  planking  and  timbers  just  beneath 
the  rubbers,  and  clenched  over  washers  fitted  on  the  inside  face 
of  every  fourth  timber.  Tapered  wedges  of  larch  or  other  suitable 
,  wood  are  fitted  between  the  timbers  and  planking,  in  way  of  the 
staple,  to  provide  a  proper  hearing  for  the  planks  on  the  timber 
and  prevent  the  former  from  splitting  when  clenching  up  the 
staples.    This  arrangement  is  shown  in  Fig.  94  d. 


186  .SHIPS'  BOATS 

An  alternative  metlKKl  of  securing  tlic  r 
profen-ed,  is  by  the  iiye  of  nuts  and  screws  ii 


I,  and  on^ 
ieu  "(  Btaples,  the 


nuts  being  hove  up  on  washers  having  the  points  of  the 
slif^htly  ulenched  over  the  nut. 

The   life-lines  are  bccketed  around  the  outside  of   the 


/> 


CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS     187 

through  the  rings,  with  full  loops  of  suflficient  length  to  reach 
within  a  short  distance  of  the  water-line.  Allowance  should, 
therefore,  be  made  for  the  sheer  of  the  boat  to  enable  the  bottom 
of  the  loops  to  remain  parallel  to  the  water-line. 

The  photograph  of  a  completed  28-ft.  lifeboat,  Class  Ia,  in 
Fig.  106,  shows  the  life-lines  secured  in  position.  Incidentally, 
this  picture  also  shows  the  relative  size  of  a  boat,  in  comparison 
with  that  of  a  person.  The  gentleman  standing  at  the  stem  of  the 
boat  is  Mr.  Thomas  Stout,  the  Head  Foreman  of  .the  Caitsburn 
Boat  Building  Co.,  Greenock,  who  has  done  much  by  his  personal 
initiatiYe  and  attention  to  details,  to  raise  the  standard  of 
workmanship  in  that  particular  district. 

The  quality  of  the  hues  should  be  considered :  2  in.  Italian 
hemp  is  very  suitable  for  the  purpose,  and  is  least  affected  by 
the  weather.  The  common  hemp  rope  sometimes  placed  on 
boats  to  serve  as  life-lines,  becomes  of  little  use  after  six  months 
of  service,  as  it  quickly  shrinks,  becomes  taut  between  the  rings 
and  out  of  the  reach  of  persons  struggling  in  the  water. 

Ordinary  eyes  screwed  into  the  rubber  are  very  objectionable, 
for  after  exposure  to  the  salt  water  they  easily  break  off. 

The  natural  thing  for  seamen  to  do  when  launching  a  boat 
outboard  from  ordinary  radial  davits  is  to  lay  hold  of  the  life- 
lines for  leverage ;  hence,  the  necessity  for  some  substantial 
security. 

It  i^  an  advantage  to  fit  a  seinefloat  in  each  bight  of  the  hemp 
rope  to  prevent  the  latter  from  twisting,  as  this  provides  a 
better  security  or  hand  grip  for  the  pei-son  holding  the  life-line. 

Equipment  Lockers. — All  Hfeboats  which  are  fully  equipped, 
including  the  "  square  stern  "  boats  of  Class  III.,  if  they  form  part 
of  the  statutory  equipment  of  a  vessel,  should  be  fitted  with  at 
least  one  locker  to  accommodate  some  of  the  details  of  equipment, 
protect  them  from  the  weather,  and  give  the  maximum  amount 
of  space  in  the  boat  for  seating  the  total  number  of  persons. 

The  usual  practice  is  to  fit  a  locker  at  each  end  of  the  boat. 
Some  shipowners  make  the  additional  provision  of  having  lockers 
fitted  under  the  thwarts. 

Portable  bottom  boards  are  placed  in  the  end  lockers  above 
the  keelson  to  enable  the  equipment  and  blankets  to  be  kept  dry. 
Hinged  doors  are  fitted  with  slip  bolts.  Portable  doors  are  not 
recommended,  because  of  their  liability  to  be  lost  overboard,  but 
where  the  mast  is  stepped  at  the  foremost  thwart,  they  can 
hardly  be  avoided. 

The  statutory  rules,  at  present,  do  not  insist  on  the  provision 


-  PLAN  - 


CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS     189 


of  these  lockers,  and  it  is  left  to  the  common  sense  of  the  individual 
to  see  that  they  are  fitted,  for  the  necessity  is  obvious  to  every 
ship's  officer. 

The  arrangements  are  shown  in  Fig.  108. 

Mast  Step. — ^The  method  of  securing  the  mast  step  is  one  of 
importance.    Instances  have  occurred,  resulting  in  loss  of  life. 


ST£P 


T7T 


:i 


4 


KIEL50H 


S  =  r..rr 


:' 


f<£EL  SO/V    V¥/TH  CHe£n 


SECTION 


\A  EVATION 
Fig.  109. — Wooden  mast  step. 


through  the  mast  and  sails  going  overboard  owing  to  the  fitting 
of  an  inefficient  step. 

In  the  first  place,  the  thwart  taking  the  mast  hasp  should  be 
increased  in  width,  and  the  arms  of  the  hasp  well  secured  to  the 
thwart  by  bolts.  Screws  are  considered  to  give  insufficient  grip 
for  the  purpose.  Details  of  mast  hasps  are  given  in  Part  VI T., 
Section  B. 

The  keelson  must  not  be  cut  to  receive  the  heel  of  the  mast, 
the  step  is  therefore  fitted  on  top  of  the  keelson  and  secured 


fffor^  S7CR 


SECTION 


ELEVATION 
Fia.  110. — Iron  mast  sU^j). 


thereto  with  good  stout  screws  and  supported  with  cheek  pieces 
covering  the  full  depth  of  keelson  and  thickness  of  step,  the  com- 
bination being  secured  with  nut  and  screw  bolts  as  shown  in 
Fig.  109. 

.  Unless  the  keelson  is  checked  over  the  timbers,  it  is  an 
advantage  to  fit  filling  pieces  between  the  timbers,  planking,  and 
keelson,  in  way  of  the  mast  step.     The  securing  bolts  through 


190 


SHIPS'  BOATS 


the  koclson  and  keel  are  arranged  to  give  support  to  the  step, 
and  so  make  the  connections  as  rigid  as  possible.  The  st«p  and 
che(*k  pieces  are  made  from  English  elm. 

An  iron  .sfrp  is  sometimes  fitted  as  illu8trat<xl  in  Fig.  110,  the 
clieek  j)ie('es  would  l)e  an  additional  advantage  and  relieve  the 
stress  on  the  screws. 

Foot  Spars  or  Stretchers. — These  must  be  of  sufficient  size 
and  strentith.  They  are  placed  in  the  most  suitable  positions  for 
tlio  cflicicMit  use  of  the  oarsmen.  In  the  largest  types  of  pulling 
boats,  lower  cross  seats  are  fitted  to  provide  the  full  seating 


rooTSP^i^ 


TA/^K  CAeA 0//VC       I 


ClifAT         ^ 


\ 


\ 


Fk;.  III. 

A,  stretcher  rl-at  litteil  to  Mlgc  strinuer. 
r».  ,.  ,,  tank  I  leading. 

('.  iMctlioil  of  littlii,?  btretchers. 

acccuninodntion  and  ar(»  also  utilised  to  serve  the  purpose  of 
stiotclicrs. 

\\ hci<»  cross-srats  are  not  littcd  in  a  boat  supplied  with 
buovaiicv  air-casos.  tlir  stretchers  are  usually  made  of  stout 
pieces  of  Aincricaii  ohn,  about  2  in.  square  in  section,  fitted  into 
cleats  attached  to  tlie  tank  cleadinu  bv  screws  from  the  back,  as 
illustrated  in  Fi;js.  Ill  u  and  c. 

In  open  l)oats  of  Class  III.  the  cleats  are  litted  to  the  bilge 
strin,i:<*r,  which  is  of  sutlicicnt  liei^ht  to  allow  the  footspar  to 
clear  the  keelson.  They  are  fastened  to  the  stringer  before  the 
latter  is  secured  in  jiosition. 

Alternative  positions  are  made  for  the  stretchers,  to  suit  the 
convenience  of  the  rowers.     (See  Fig.  Ill  a.) 

Towing  Bollards.— -On  a  passenger  vessel  where  a  large  number 


■construction   of   class   Ia   open   lifeboats     191 

o£  lifeboats  are  carriwl,  including  one  or  more  motor  bnata,  the 
latter  serve  a  very  useful  purpose  in  keeping  the  pulling'  boat* 
fj^ljether  should  the  necessity  arise.  Provision  should  therefore 
be  made  in  all  the  boats  to  fit  towing  bollanls,  to  enable  the  motor 
l)uat«  Ui  conne<'t  up  with  the  pulling  boats  and  relieve  the  oarsmen. 

TKe  use  of  the  ring  bolt  in  the  stem  for  this  purpose  should 
be  avoided,  as  experience  proves  this  practice  to  be  one  accom- 
panied with  grave  risk  to  the  occupants  of  the  boat.  The 
Admiralty  insist  on  the  fitting  of  towing  liollards  in  all  cutters 
and  whalers,  to  enable  large  numbers  of  men  to  be  safely  carried 
and  the  boats  towed  behind  a  motor  or  tug-boat. 

A  suitable  method  of  fitting  this  bollard  ia  illustrated  in 
Fig.  108.  It  consists  of  a  portable  strongback,  made  from 
Danzig  or  English  oak,  which  fits  into  clamps  secured  to  the 
gunwale.  These  clamps  may  be  of  wrought  iron,  but  a  neater 
job  is  given  by  a  metal  castii^,  owing  to  the  difficidty  of  securing 
the  two  bevels  at  the  gunwale.  The  starboard  clamp  is  arranged 
to  hinge  to  permit  of  the  insertion  of  a  strongback.  Attached  to 
the  centre  of  the  strongback  is  a  wrought-iron  hasp,  or  clamp, 
which  supports  the  bollard.  The  latt€r  is  made  from  EngUsh 
ash,  with  a  square  section  having  its  edges  roimded  to  accommo- 
date the  tow-rope. 

The  heel  of  the  bollard  is  circular,  and  secured  in  position  by 
piercing  the  gangboard.  The  bollard  cannot  jump  or  lift  pro- 
vided a  drop  uose-pin  is  fitted  beneath  tho  gangboard  passing 
through  the  heel  of  the  bollard,  and  having  its  upper  surface 
flattened  to  prevent  any  movement.  The  pin  is  secured  to  the 
boat  by  a  chain  lanyard. 

Plugs. — Each  lifeboat  is  fitted  with  two  plugs  for  each  plug- 
hole. The  position  must  be  one  of  easy  access,  and  the  bottom 
boards  arranged  accordingly.  Tho  box  to  take  the  biimacle 
compass  is  place<l  imder  the  thwart  immediately  on  the  fore  side 
of  the  stem-sheets,  to  allow  the  ateeraman  a  clear  view  of  the 
compass.  This  box  should  be  arranged  to  be  well  clear  of 
tbe  plugs. 

The  common  practice  is  to  fit  a  cork  plug  into  a  brass  socket, 
as  shown  in  Fig.  112  a.  This  litting  cannot  be  recommended, 
as  the  writer  has  repeatedly  found  it  to  leak,  particularly  at 
the  metal  spindle  passing  through  the  cork  plug.  The  material 
in  Uie  srxiket  is  paired  down  to  such  an  extent  as  to  make  the 
arrangement  of  little  value.  To  serve  its  purpose,  a  plug  must  bo 
of  substantial  scantling  and  should  make  a  watertight  connection 
with  the  socket. 


192 


SHIPS'  BOATS 


Fig.  112  B  shows  an  automatic  plug  sometimes  fitted  to  steel 
boats. 


METAL  SOCKET 


—  SECTION- 


rsgT 


HAMMenrL}  ovfff 


-  SELCTIOM 


^-.      SOCKET       ,. 

"2)     .   -  ^.     -2) 


c 


-  PLAN  - 


SNELL  plating 


B 


^t'        *•..    COVtfp  RAISED 
V-*  ^CLJP LATCH 


CLIP-*- 


THUMB 

LCAre 


Li^rffeff^    K       COVER 


"•^ — wr^'i"' 


-SeCTION- 

HiNce 


CuiP 


-PLAN- 


Fio.  112. — IXtailH  of  plugs. 


Fig.  112  c  is  a  very  useful  and  substantial  type  of  plug.  It  cannot 
be  detached  from  the  socket,  and  by  unscrewing;  it  allows  the 


CONSTRUCTION  OF  CLASS  Ia  OPEN  LIFEBOATS     193 

water  to  drain  from  a  hole  in  Uie  side  of  the  spigot.  A  leather 
washer  makes  a  watertight  connection. 

Fig.  112  D  is  an  excellent  fitting,  placed  on  the  market  by 
Ellisons  (Liverpool),  Limited,  and  named  the  "  Agrippa  "  Patent 
Boat  Plug.  It  consists  of  a  screwed  socket,  attached  to  which 
is  a  hinged  cover  faced  with  leather.  The  cover  is  brought  to 
bear  on  the  seating  of  the  socket  with  the  aid  of  thumb  cleats 
on  a  clip  hatch,  and  wedged  in  position  by  the  latter  catching  the 
clip^.  attached  to  the  socket. 

Ordinary  soft  pine  plugs  are  sometimes  fitted,  attached  to  the 
boat  by  strong  lanyards. 

It  is  good  practice  to  secure  a  pad  piece  on  the  outside  surface 
of  the  planking  in  way  of  the  plug  hole,  particularly  when  soft  pine 
plugs  are  used.  The  thickness  of  the  planking  is  considered  to 
be  insufficient  to  take  the  sockets  or  to  provide  ample  material 
for  the  securities  without  being  pierced. 

Bottom  Boards,  Stern  and  Head  Sheets. — To  protect  the 
timbers  and  fastenings  of  plank  landinjrs,  bottom  boards  are  fitted 
and  made  readily  portable.  Care  should  be  exercised  to  ascertain 
that  they  clear  the  biscuit  tanks,  because  it  is  usual  to  fit  the 
latter  after  the  bottom  boards  are  in  position. 

The  bottom  boards  come  in  for  a  good  deal  of  rough  usage 
and  should  be  made  from  fairly  tough  material,  such  as  teak, 
elm,  or  larch,  not  less  than  |  in.  in  thickness  and  well  secured 
together. 

The  stern  and  head  sheets  are  the  platforms  situated  forward 
and  aft  at  the  ends  of  the  boat,  and  are  iLsually  made  portable. 
The  common  practice  is  to  make  them  from  ordinary  flooring,  but 
good-class  boatbuilders  fit  portable  gratings,  which  finish  off  the 
appearance  of  the  boat  without  increasing  tJie  cost  to  any 
extent. 

Pad  Pieces  in  way  of  Stowage  Chocks. — To  protect  the  plank 
landings  from  the  effects  of  launching  and  housing  the  lifeboats  in 
their  supporting  chocks  on  deck,  pad  pieces  should  be  fitted,  for 
about  15  in.  in  length,  to  the  outside  surface  of  the  planking  in  way 
of  the  chocks.  In  order  to  maintain  a  flush  appearance,  in  a 
clinker-built  boat,  tapered  pieces  are  fitted  in  a  similar  manner 
to  an  inside  doubling,  and  secured  to  the  timbers. 

The  fitting  of  the  supporting  chocks  to  the  form  of  the  boats 
now  becomes  an  easy  procedure,  and  as  the  standard  positions 
for  these  are  situated  at  a  quarter  the  length  of  the  boat  from 
the  ends,  the  boat])uilder  can  secure  these  pad  pieces  before  the 
boat  leaves  the  vard. 

O 


194  SHIPS'  BOATS 

Inspection  during  Construction. — ^All  boats  which  form  a  part 
of  the  statutory  equipment  of  a  vessel,  must  be  constructed  under 
the  supervision  of  a  ship  surveyor  from  the  Marine  Department 
of  the  Board  of  Trade. 

The  Admiralty  have  a  special  staff  to  undertake  the  oversight 
of  all  types  of  pulling  and  motor  boats,  building  for  the  Naval 
Service.  The  Overseers  devote  their  whole  time  to  this  particular 
work ;  they  have  a  very  detailed  specification  to  follow,  and  know 
exactly  what  they  want.  The  supervision  and  the  construction 
therefore  proceed  along  satisfactory  lines. 

The  inspection  must  be  carried  out  systematically,  and  the 
visits  arranged  to  prevent  any  delay  to  the  construction.  This 
can  only  be  done  by  the  appointment  of  inspectors  who  have  had 
some  experience  in  the  profession  and  are  permitted  to  devote  a 
reasonable  amount  of  time  for  the  necessary  supervision. 

There  should  be  at  least  four  separate  visits  for  inspecting 
particular  portions  of  the  boat  during  construction,  which  are 
as  follows  : — 

1 .  Wlien  the  frame  is  complete,  i.e.  the  keel,  stem,  stempost, 
aprons,  deadwoods,  and  hog-piece,  have  been  trimmed,  secured, 
and  ready  for  painting  or  varnishing.  An  identification  number 
is  then  cut  in  the  keel,  wliich  follows  the  boat  throughout  its  life 
on  board  anv  vessel. 

The  quality  of  the  material,  particularly  the  crooks,  together 
with  the  fastenings,  can  thus  be  examined  before  the  planking  is 
commonced  or  any  i)aint  applied. 

2.  Inspection  of  planking  before  timbering.  To  enable  a 
good  soaking  coat  of  whito-load  paint  to  be  worked  on  the  inside 
surface  of  the  planking,  and  thus  allow  the  material  behind  tlie 
timbers  to  bo  painted,  it  is  necessary  to  inspect  the  planking 
immediatoly  before  the  timbers  are  bent  into  position.  Oppor- 
tunity is  taken  to  reject  any  defective  planks,  particular  attention 
being  paid  to  the  efFicioncy  of  the  soleing,  the  snapeing  away 
at  the  hood-ends  and  the  faying  surface  of  the  apron.  Where 
doublings  are  required  they  should  be  fitted  and  fastened  before 
timbering. 

3.  Inspection  of  internal  fittings,  final  inspection  of  planking 
and  fastenings  before  painting.  It  is  necessary  to  carefully 
examine  all  securities  at  the  rising,  stringers,  thwart  knees, 
thwart  ends,  mast  hasp,  mast  step,  gangboard,  lifting-hooks,  etc., 
and  watch  for  butted  timbers  at  the  hog-piece.  Inspect  the 
])uoyancy  air-cases,  mea.sure  their  capacity,  and  test  them  by 
immersing  in  a  tank  of  water.     Measure  tlie  length,  breadth. 


CONSTRUCTION  OF  CLASS  Is  OPEN  LIFEBOATS     195 

and  depth  of  the  boat ;  ascertain  the  capacity  by  Stirling's  Rule 
if  required. 

4.  Final  inspection  before  delivery.  It  is  necessary  to  open  out 
the  portable  floors  in  lockers,  stem  and  head-sheets,  to  ascertain 
that  all  shavings  have  been  cleared  out  of  the  boat.  Make  sure 
that  the  lifting-hook  securities  are  satisfactory.  Inspect  the 
various  hull  fittings.  Ship  the  rudder  and  ascertain  if  there  is 
ample  clearance.  Try  the  steering  oar  in  the  grommet.  Make  sure 
there  is  suflficient  seating  accommodation  for  the  total  number  of 
persons  allocated  to  the  boat.  Step  the  mast,  spread  the  sails, 
watch  the  traveller  to  see  if  there  is  ample  clearance.  Try  the 
sheet  ropes  for  length.  Secure  the  shrouds.  Examine  details 
of  equipment.  See  that  the  approved  items  of  equipment  are 
secured  to  the  boat  with  lanyards.  Carefully  inspect  the  plugs. 
Secure  the  water  breakers  with  lashings.  Look  at  the  life-lines 
and  try  all  crutches  in  place.  Cut  dimensions  on  the  correct  side 
of  the  stem,  and  stamp  the  date  of  final  inspe(^;tion  and  initials 
of  the  Surveyor. 

A  few  saUent  features  to  remember — 

Secure  the  interest  and  company  of  the  foreman  at  every  visit 
to  the  yard. 

Be  straight  and  definite  in  all  your  demands. 

Mark  defects  on  the  boat,  and  give  your  requirements  in 
writing  before  leaving  the  yard. 

Don't  keep  anyone  waiting. 

Don't  ventilate  your  knowledge.  You  are  "  summed  up  " 
after  ten  minutes'  conversation  with  a  practical  boatbuilder. 

Be  of  some  assistance,  don't  keep  all  the  information  stowed 
away  in  portfolios  at  the  office. 

The  details  associated  with  Ufting-hooks,  sails,  equipment, 
etc.,  are  dealt  with  in  their  own  particular  section. 


SECTION  B.--CONSTRUCTION  OF  CLASS  Ib  OPEN 

LIFEBOATS 

The  midship  section  of  a  Class  Ib  open  lifeboat  is  shown  in 

The  construction  is  identically  the  same  as  that  of  a  lifeboat 
of  Class  Ia,  with  the  exception  that  external  buoyancy  is  fitted 
in  addition  to  the  watertight  air-cases,  and  with  a  slight  reduction 
in  capacity  of  the  internal  buoyancy. 


196  SHIPS'  BOATS 

The  total  volume  of  the  watertight  air-cases  in  the  Class  Ia 
lifeboat  must  be  at  least  equal  to  one-tenth  of  the  cubic  capacity 
of  the  boat,  and  in  the  case  of  the  Class  Ib  lifeboat,  the  volume  of 
internal  buoyancy  given  by  the  air-cases  must  be  at  least  equal  to 
7|  per  cent,  of  the  cubic  capacity  of  the  boat. 

When  a  lifeboat  of  this  class  is  constructed  of  metaJ,  an 
addition  should  be  made  to  the  cubic  capacity  of  the  airtight 
compartments  (internal  buoyancy),  so  as  to  give  it  buoyancy 
equal  to  that  of  the  wooden  boat. 

If  the  exterfial  buoyanaj  is  made  up  from  cork,  its  volume,  for  a 
wooden  boat,  should  be  not  less  than  thirty-three  thousandths 
of  the  cubic  capacity  of  the  boat ;  if  of  any  material  other 
than  cork,  its  volume  and  distribution  should  be  such  that 
the  buoyancy  and  stability  of  the  boat  are  not  less  than  that 
of  a  similar  boat  provided  with  external  buoyancy  of  cork. 

If  the  internal  caj)acity  of  a  Class  Ib  lifeboat  is  500  cub.  ft. 
the  capacity  of  the  internal  buoyancy  tanks  will  be — 

7 J%  of  5(X)  =  7-5  X  5  =  37-5  cub.  ft. 

and  the  volume  of  cork  external  buoyancy — 

500  X  -  ^     =16-5  cub.  ft. 
1000 

This  gives  a  total  volume  of  54  cub.  ft.,  being  an  addition  of 
4  cub.  ft.  to  the  50  (jub.  ft.  of  watertight  air-cases  required 
for  a  Class  I  a  lifeboat  of  the  .same  dimensions. 

Fig.  113  shows  in  detail  how  tliis  outside  buoyancy  is  made  up 
and  secured  to  the  structure  of  the  boat. 

The  same  principle  of  constniction  is  applicable  to  the 
Class  II A  open  lifeboats. 

The  use  of  ruslies,  cork  sliavings,  loose  granulated  cork,  or 
any  other  loose  graimlated  substance,  and  the  use  of  apparatus 
dependent  upon  inflation  l)y  air,  are  not  permitted  for  the  purpose 
of  external  buoyancy. 

The  quality  of  the  cork  must  be  of  the  very  best  and  obtained 
in  long  continuous  slabs,  well  piimed  together  and  to  a  wooden 
backboard  not  less  than  \  in.  in  thickness. 

Its  form  in  section  should  be  such  that  it  will  not  be  liable  to 
be  torn  away  by  contact  with  ilie  ship's  side  when  the  boat  is  being 
lowered,  and  its  sliape  maintained  by  means  of  wood  sectional 
diaphragms  secured  to  the  backboard. 

The  operation  of  pinning  and  securing  the  cork  must  be 


CONSTRUCTION  OF  CLASS  Ib  OPEN  LIFEBOATS    197 


efficiently  done,  otherwise-  the  external  buoyancy  becomes  of 
veiy  little  use  after  the  boat  is  in  service. 


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Fio.  113. — Mctiiod  of  fitting  outside  buoyancy  to  lifeboats  of  Classes  Ib  and  11a. 

The  cork,  backboard,  etc.,  are  then  covered  with  a  good  quality 
waterproof  canvas  and  well  painted. 

The  cork  sections  are  made  in  tbree  lengths,  on  each  side  of  the 
boat,  and  secured  to  the  planking  in  such  a  position  that  its  lower 


19^  SHIPS'  BOATS 

edge  amidrihipa  is  a  few  inches  above  the  kwd  wmter-hne  of  the 
boat.  They  are  made  portable  bv  fitting  apper  and  lower  stnp6 
of  wood  to  act  aa  a  bearing  for  securing  thereto  the  external 
buoyancy.  These  battens  are  about  2J'  x  IJ'  and  secured  to 
the  timbers  by  clenched  fastenings ;  they  usually  take  the  run 
of  the  plank  landings. 

Galvanised  iron  straps  about  3'  X  i^  with  strong  hinges 
at  the  top  and  IxAUmi,  and  spaced  not  more  than  2  ft,  6  in.  are 
arranged  to  support  the  several  lengths  of  cork  combination. 
In  way  of  the  butts  the  breadth  of  the  straps  is  slightly  increased 
to  provide  sufficient  bearing  for  the  two  ends.  The  edges  ot 
the  iron  straps  are  well  rounded  to  prevent  damage  to  the  canvas 
and  cork. 

Tlie  upper  and  lower  battens  provide  an  air  space  between 
the  plankiri;:  and  the  external  buoyancy.  The  hinges  attached 
Uj  the  straps  are  secured  to  the  battens  by  three  screws  care 
being  exercised  that  they  do  not  pierce  the  planking.  The  pins 
in  the  liin^^'es  should  be  made  of  metal. 

The  two  end  lengths  are  slightly  tapered ;  and  to  prevent 
damage  t<;  tlie  cork  when  bringing  the  boat  alongside  a  jetty  or 
accommodation  ladder,  wooden  sliver  pieces  are  secured  to  the 
planking',  as  shown  in  Fig.  132. 

The  usual  procedure  is  for  the  boatbuilder  to  fit  the  battens 
and  secure  them  in  position,  make  the  backboard  to  suit,  prepare 
tlie  diaplira<(m  sections  and  secure  them  to  the  backboard.  Wood 
He(  tioim  are  forwarded  to  tlie  smith  to  enable  him  to  prepare  the 
iron  strups  and  hmges.  The  backboard,  etc.,  is  then  given  to 
the  sailinaker  or  a  maker  of  life-jackets,  who  prepares  the  cork 
slabs,  secures  iliem  to  the  backboard,  and  covers  the  whole  with 
tlni  ai)prov(Hl  type  of  canvas. 

Tlie  (|uality  of  Uui  cork,  etc.,  should  be  inspected  before  it  is 
covered  witli  llie  cuiivaH. 

Ill  eases  where  the  stability  of  boats  has  been  found  to  be 
delicient,  and  in  order  to  increase  the  moment  of  inertia  of  the 
watiu*  plane,  ilw  iittin«:  of  cork  outside  buoyancy  has  often  been 
resorted  to. 

It  is  inii^ortant  to  remember  in  arranging  the  overhang  of  the 
davit.s  that  account  must  be  taken  of  the  additional  breadth 
LMven  bv  the  outside  buovancv  attached  to  a  Class  Is  lifeboat. 
The  rtH'o.auised  breadth  of  the  boat  is  the  greatest  breadth  to 
outside  of  planking,  and  not  to  the  outside  of  ext<jrnal  buoyancy. 
The  diam(*ter  of  davitvS  carrying  this  type  of  boat  is,  therefore, 
larger  than  a  davit  under  which  is  stoweil  a  lifeboat  of  Class  Ia, 


CONSTRUCTION  OF  CLASS  III.   BOATS         199 

on  account  of  the  greater  outreach  necessitated  by  the  fitting  of 
external  buoyancy. 


SECTION  C— CONSTRUCTION  OF  CLASS  III.  BOATS 

The  piidship  section  of  a  Class  III.  boat  is  illustrated  in  Fig.  7. 
This  type  of  boat  is  constructed  in  a  similar  way  to  an  open 
lifeboat  of  Class  Ia,  with  this  exception,  that  buoyancy  air-cases 
are  not  fitted. 

The  construction  is  practically  confined  to  the  "  clinker " 
method.  They  very  rarely  exceed  22  ft.  in  length ;  in  reaUty  they 
are  Ught  pulling  boats,  and  it  is  quite  probable  they  are  used 
with  greater  frequency  than  the  larger  lifeboats  carried  on 
board  a  cargo  vessel. 

Passenger  vessels  are  not  permitted  to  carry  boats  of  Class  III. 

In  a  foreign-going  steamship,  not  certified  to  carry  more  than 
twelve  passengers,  and  certain  other  vessels  mentioned  in 
Section  A,  Part  11. ,  a  proportion  of  the  total  number  of  boats  to  be 
carried  may  be  of  Class  III.  As  an  example,  in  the  case  of  the 
foreign-going  steamship  referred  to,  if  the  total  number  of  lifeboats 
required  by  the  Life-saving  AppUances  Rules  exceeds  two,  a  boat 
of  Class  III.  may  be  carried  in  lieu  of  one  of  them,  and  if  the 
number  exceeds  three,  one  or  two  boats  of  Class  III.  may  be 
carried  in  Ueu  of  the  same  number  of  lifeboats.  The  Class  III. 
boats  as  well  as  the  Class  I.  lifeboats,  should  be  attached  to  davits. 

It  is  important  to  remember  that  when  a  vessel  is  certified  to 
carry  a  number  of  passengers,  not  exceeding  twelve,  and  which, 
if  it  were  not  certified  to  carry  passengers,  would  be  subject 
to  rules  governing  foreign-going  steamships  not  certified  to  carry 
passengers,  or  a  steamship  trading  within  home  trade  limits,  but 
not  certified  to  carry  passengers,  as  the  case  may  be,  it  is  subject 
to  the  rules  governing  the  boats  for  the  latter  classes,  and  not  to 
those  in  any  other  class.  Under  these  conditions  a  certain 
number  of  Class  III.  boats  may  be  carried,  but  steamships  certified 
to  carry  more  than  twelve  passengers,  must  have  buoyancy  air-cases 
fitted  to  the  whole  of  the  open  lifeboats  carried  on  board. 

Every  boat  which  is  carried  on  board  a  vessel  is  classified, 
provided  that  it  forms  a  part  of  the  statutory  equipment  of  the 
vessel.  Boats  which  are  carried  in  addition  to  the  equipment, 
such  as  working  boats  or  the  captain's  dinghy,  need  not  be 
classified. 

Class  III.  boats  must,  therefore,  be  built  under  inspection, 


200  SHIPS'  BOATS 

and  conform  to  all  the  regulations  issued  by  the  Board  of  Trade 
as  to  scantlings  and  details  of  construction. 

In  the  case  of  defective  planking  or  damage,  a  Class  I.  lifeboat 
possesses  the  buoyancy  air-cases  as  a  secondary  means  of  keeping 
her  afloat,  but  the  Class  III.  boats  depend  entirely  upon  the 
quality  of  material  and  workmanship  for  maintaining  herself  in  a 
seaworthy  condition.  Hence,  the  importance  of  careful  scrutiny 
during  the  progress  of  construction. 

Some  builders  are  inclined  to  look  upon  these  boats  as  being 
of  less  importance  than  the  lifeboats,  but,  strictly  speaking,  they 
should  be  constructed  with  even  greater  care  than  the  larger 
boats. 

There  are  bound  to  be  anomalies  in  all  rules,  but  many  people 
cannot  understand  why  it  shoidd  be  necessary  in  the  case  of  a 
small  sailing  vessel,  say  a  ketch  of  40  tons  gross  tonnage, 
and  running  between  Glasgow  and  Ayr,  carrying  an  open  boat 
of  Class  III.  sufficient  to  accommodate  all  persons  on  board, 
should,  immediately  a  small  motor  is  inserted  as  an  auxiliary 
means  of  propulsion,  be  required  by  the  Life-saving  Appliances 
Rules  to  carry  a  lifeboat  of  Class  1.,  i.e.  buoyancy  air-cases  must 
be  fitted  to  the  Class  III.  boat. 

The  installation  of  a  motor  has  converted  the  sailing  vessel 
into  a  steamer  and  brought  her  under  a  new  classification  of  the 
L.S.A.  Rules,  but  tlie  necessity  does  not  appear  clear. 

It  is  important  to  remember  that  all  Class  III.  boats  must  be 
equipped  in  every  detail  the  same  as  the  Class  Ia  lifeboats 
carried  on  board. 

Ill  IG-ft.  boats  and  below,  it  is  not  usual  t(;  fit  side  seats  extend- 
ing over  the  wliole  of  the  tliwurts  as  in  a  lifeboat  of  Class  I.  of 
similar  dimen.sir)ns.  The  amount  of  equipment  which  must  be 
(•allied  in  accMjrdaiicc  with  the  reirulations  is  sufficient  to  limit 
tlie  number  of  persons  whicli  can  be  reasonably  assigned  to  the 
boat.  Very  few  boats  of  Class  III.  are  constructed  "double 
bowed/'  they  usually  have  S(|uare  sterns  which  allow  greater 
accoiiimodatioii  on  the  stern  benclies.  In  boats  of  18  ft.  in  length 
and  upwards  it  becomes  necessary  to  extend  the  seats  in  order  to 
provide  sufficient  area  for  seatin<:;. 

SECTION    D.— CONSTRUCTION    OF    CLASS    IIa    OPEN 
LIFEBOATS   WITH  COLLAPSIBLE  BULWARKS 

A  GENKRAL  description  of  the  diilerences  between  the  various 
types  or  clashes  of  boats,  has  already  been  given  in  Section  B  of 


I 


^^  thici 
^H  tiiicl 


CONSTRUCTION  OF  CLASS  IIa  OPEN  LIFEBOATS    201 

Part  n.,  aud  the  purpose  of  grouping;  tlie  various  aectiona  under 
Pait  IV.  is  to  ptuvide  discussiou,  in  fuller  detail,  of  the  mcthoda 
of  constructioQ  iu  each  individual  class  of  boat, 

Fi(;.  4  gives,  in  outline,  the  niidahip  section  of  a  Class  IIa 
open  lifeboat,  and  it  will  be  seen  that  it  differs  in  form  from 
the  ordinaiy  type  of  open  lifeboat  (Class  L),  having  a  much  lower 
freeboard  to  the  top  of  the  solid  hidl.  Additional  protection  ia 
obtained  by  the  fitting  of  collapsible  bulwarks. 

Comparing  boats  of  the  same  length  but  differing  in  claaa 
we  find  that  the  freeboard  of  a  28-ft.  lifeboat  of  Class  Ia  is  about 
24  in.,  and  that  of  a  28-ft.  lifeboat  of  Class  IIa  is  9  in.  measured 
to  the  solid  hull,  but  with  the  bulwarks  fixed  in  position,  is 
increased  to  about  33  in. 

The  provision  of  collapsible  bulwarks  allows  this  type  of  boat 
to  be  stowed  under  open  lifeboats  of  Class  I.,  which  are  attached 
to  davits,  or  they  may  be  stowed  inboard  one  above  the  other 
or  singly,  provided  trauaporting  arrangements  are  fitted  under 
the  boats  to  bring  them  under  the  davits  with  rapidity,  for 
launching  overboard. 

This  class  of  boat  appears  to  find  most  favour  with  ship- 
owners  who  require  to  be  supplied  with  a  number  of  lifeboats 
having  collapsible  bulwarks. 

The  lengths  of  the  boats  vary  from  24  to  3U  ft.,  the  breadths 
from  8  to  9  ft.,  and  the  depth  without  bulwarks  is  about  2  ft. 

Watertight  metal  air-cases  are  fitted  at  the  sides  in  a  similar 
fashion  to  Class  I.  boats,  in  order  to  provide  the  necessary  reserve 
of  buoyancy. 

The  general  structure  of  the  hull  is  made  up  of  two  thick- 
nesses of  woikI  planking,  worked  in  a  fore-and-aft  directi<m,  and 
flo  arranged  that  the  seams  of  the  two  thicknesses  break  joint 
one  with  the  other.  An  approved  fabric  is  worked  between  the 
two  thicluiesses  of  plonking. 

For  vessels  whose  trade  continually  takejs  them  through  the 
tropics,  it  is  very  essential  that  the  planking  should  be  of  material 
that  is  least  affected  by  the  extremes  of  teniperature.  Two 
thicknesses  of  Honduras  or  Lagos  mahogany  make  an  excellent 
hull,  and  it  is  the  opinion  of  many,  that  woi>d  of  inferior  quality 
to  mahogany  should  not  be  permitted  in  these  classes  of  boats, 
as  they  are  not  used  or  inspected  with  the  same  frequency  as 
Class  I.  boats  ot  the  open  type.  In  cases  where  passenger  vessels 
itantly  employed  in  a  temperate  climate,  the  double 
thickness  of  wood  planking  is  sometimes  made  up  of  an  inner 
tluckneas  of  larch  and  an  outer  thickness  of  yellow  pine. 


202  SHIPS'  BOATS 

The  boat  is  double  bowed,  having  a  "  deck  "  at  the  ends  and 
over  the  buoyancy  tanks  at  sides,  with  a  central  open  well  the 
full  depth  of  the  hull.  The  deck,  or  covering,  over  lie  buoyancy 
tanks  forms  the  upper  surface  of  the  hull  bom  which  the  free- 
board is  measured.  Above  the  '^  deck  "  are  fitted  the  collapsible 
bulwarks,  which,  hinge  down  in  their  stowing  position. 

The  standard  type  of  Class  IIa  lifeboat  at  one  time  consisted 
of  the  hull  as  described,  with  solid  wooden  bulwarks  fitted  for  a 
little  more  than  half  the  length  of  the  boat  amidships,  in  way  of 
the  straight  sides.  Between  the  wooden  bulwark  and  the  ends  of 
the  boat  rotproof  and  waterproof  canvas  was  fitted.  The  bulwarks 
were  kept  in  position  by  hinged  stanchions,  which  locked  them- 
selves in  the  upright  position.  Thwarts  were  also  fitted  and 
arranged  to  hinge  down  in  a  similar  way  to  the  bulwarks.  They 
were  connected  together  in  two  sections,  so  that  the  forward 
section  would  hinge  towards  the  stem  and  the  after  section 
towards  the  stem.  Locking  arrangements  were  also  provided  for 
the  thwarts. 

The  first  operation  is  to  lift  the  bulwarks  and  then  the 
thwarts ;  wlien  the  latter  are  in  position  and  persons  seated 
thereon,  movement  cannot  take  place ;  the  upper  structure  is 
thus  well  secured. 

Outside  buoyancy  made  up  of  solid  cork  and  secured  by  the 
method  described  in  Section  B,  is  fitted  on  each  side  of  the 
boat,  immediately  above  the  water-line. 

Fig.  114  shows  the  old  standard  type  of  Class  IIa  open  life- 
boat, undergoing  the  Board  of  Trade  rowing  tests,  with  the 
full  number  of  persons  on  board,  each  one  being  provided 
with  a  life-jacket.  This  type  of  life-jacket  has  now  been  con- 
demned. The  particular  boat  illustrated  was  constructed  by 
Messrs.  Hu^^li  McLean  and  Son,  of  Go  van,  who  have  had  a  very 
extensive  experience  in  this  and  other  types  of  lifeboats  with 
collapsible  bulwarks. 

The  following  details  of  construction  are  given  for  a  lifeboat 
of  standard  size.  viz.  : — 

I^ongth.  Breadth.  Depth. 

30'  U"     X     9'  0"     X     1'  lir 

Scantlings. — These  are  based  upon  the  assumption  that  the 
structural  strength  is  such  that  the  boat  will  be  able  to 
support  a  deadload  equal  to  25  per  cent,  greater  than  the 
actual  service  load,  when  supported  by  the  slings  and  their 
attacliiiients. 


204 


SHIPS'  BOATS 


KeBl. — Should  be  of  oak  or  Americsu  rock  elm,  2^'  X  2J', 
and  free  from  knote  and  short  grain. 

Stem  and  Sternpost. — Should  be  of  oak,  and  cut  from  timber 
grown  to  shape,  attaclied  and  secured  to  Uie  keel  by  a  horizontal 
scarph,  as  shown  in  Fig.  115.  Nut  and  screw  bolte  are  to  be 
preferred  for  the  securities,  having  square  or  oblong  heads 
to  prevent  turning. 

Deadwood  and  Apron. — If  a  suitable  crook  can  be  obtained. 


Hie  clwtilw.iinl  iiiiil  upiiin  slioukl  be  in  one  piece,  otherwise 
tlicy  arc  lip-scai])hed  t"j;cther.  They  arc  aided  so  as  to 
pruticrve  a  good  fayiug  Hurfucu  t'ur  (lie  liood-cnds  of  the  planking. 
The  seciiritic'j  at  the  liooil-eniiH  urc  provided  by  means  of  one 
row  of  brass  sercwK  Jieiiru.-it  llio  rabbet,  and  a  second  row  of 
tojipfi-  roise-Leadud  nail.s. 

Owiim  to  the  lilufT  I'uds  and  full  form  of  boat,  there  is  a 
[^rcat  doal  of  initial  slrcse;  i>ii  (ho  plaiikiu^  towards  the  stem  and 


CONSTRUCTION  OF  CLASS  IIa  OPEN  LIFEBOATS    205 

stemposty  which  Decessitates  careful  treatment  of  the  combina- 
tions at  the  ends,  and  provision  must  be  made  for  fair  surfaces 
to  take  the  securities  to  prevent  any  undue  stress  on  the  planks. 
Hog*Pleee. — This  is  fitted  in  one  piece  the  full  length  of  the 


5  BUlHNeAO 


Fio.  115b. — C/ombinations  at  the  ends  of  a  ClasH  IIa  lifeboat. 

boat,  checked  under  and  secured  to  the  dead  woods.  The  thick- 
ness should  not  be  less  than  \\  in.,  and  the  width  so  arranged  as 
to  give  at  least  1  in.  each  side  of  the  keel  for  the  landing  of  the  gar- 
board.  The  hog-piece  is  connected  to  the  keel  by  through  fastenings. 


206  SHIPS'  BOATS 

Bulkheads. — Owing  to  the  particular  form  of  this  type  of 
boat,  having  great  breadth  in  comparison  with  its  depth,  the 
longitudinal  and  transverse  strength  is  maintained  by  providing 
solid  longitudinal  and  transverse  bulkheads,  fitted  the  full  depth 
of  hull. 

The  purpose  of  these  bulkheads  is  not  to  divide  the  hull  into 
watertight  compartments,  as  in  pontoon  boats  of  Classes  Ic, 
11b,  and  He,  but  to  stiffen  up  the  boat  for  supporting  the  number 
of  persons  which  can  be  carried. 

Drain  holes  are  cut  in  the  heel  of  all  the  bulkheads,  and  of 
suflScient  size  to  allow  water  to  flow  freely  towards  the  centre  of 
the  boat. 

When  these  bulkheads  are  fitted  together  they  form  a  skeleton 
frame  which  dispenses  with  the  necessity  of  erecting  special 
moulds  for  the  purpose  of  planking. 

(a)  Lifting  Bulkheads. — A  transverse  bulkhead  is  fitted  at 
each  end  of  the  boat  to  take  the  chain  slings  or  lifting  gear. 
The  scantlings  are  in  excess  of  tlie  other  bulUieads.  They  are 
fitted  in  one  piece,  if  possible,  not  less  than  If  in.  in  thickness, 
of  English  elm  or  Oregon  pine,  preferably  the  former. 

These  bulkheads  extend  the  full  breadth  of  the  boat  at  a 
distance  from  the  ends  most  suitable  for  the  spread  of  davits. 
If  they  cannot  be  obtained  in  one  piece,  the  separate  portions 
should  be  well  connected  together  with  iron  straps. 

(6)  Longitudinal  Bulwarks, — Two  of  these  are  fitted  extending 
the  full  length  of  the  boat,  between  the  transverse  lifting  bulk- 
heads, one  on  each  side  of  the  middle-line  at  a  suitable  distance 
to  allow  sufficient  space  for  the  accommodation  of  the  buoyancy 
tanks.  They  are  usually  made  of  pitch  pine  and  scored  over 
the  timbers,  connected  to  the  lifting  bulkheads  by  galvanised 
angle  bars,  4"  X  2Y,  havin*^'  at  least  four  |-in.  nut  and  screw  bolts 
in  each  flan'^e.     The  ends  of  the  screws  are  clenched  over  the  nuts. 

The  lon<^itudinal  bulkheads  at  the  sides  are  either  extended 
beyond  the  transverse  lifting  bulkheads,  to  the  ends  of  the  boat, 
or  a  middle-line  bulkhead  is  fitted  as  shown  in  Pigs,  115a  and 
lir)B. 

(c)  Transverse  Wing  Bulkheads, — These  are  usually  made 
from  larch,  \\  in.  in  thickness,  four  in  number,  fitted  each  side 
of  the  boat,  between  the  longitudinal  bulkheads  and  planking, 
and  connected  to  the  former  by  galvanised  iron  angle  bars, 
^Y  X  2^",  and  secured  by  at  least  three  J-in.  nut  and  screw  bolts 
tlirou<rh  each  flanjre. 

(rf)  Transverse   Well  Bulkheads, — Two  in  number  are  fitted 


ONSTRUCTION   OF   CLASS  IIa  OPEN  LIFEBOATS    207 

t  the  well  between  the  longitudinal  bulkheads,  and  connected 
9  them  by  angle  bars  of  the  same  size  as  those  fitted  to  the  wing 
Ikbeads. 

(e)    Diagonal    Bulkhmds. — In    addition   to    the   middle-line 

_     "Jiead   at   the   ends,   two   diafioual   bulkheads,   made   from 

larch  IJ  in.  in  thickness,  are  fitted  between  the  former  and  the 

planking.     These    have   sometimes    been    dispensed    with    and 

extra  lieavy  timbers  6tt«l  at  the  ends  as  compensation. 

Timbers.— Of  American  elm,  IJ'  x  %",  to  extend  from  deck 
to  deck  in  one  piece  and  notchud  into  gimwale  and  well  secured 
to  the  latter,  the  longitiidmal  bulkheads,  and  the  ling-piece, 
before  procewling  with  the  planking. 

The  spacing,  centre  to  centre,  is  six  inches. 

Between  the  diagonal  bulkheads  and  stem  or  sternpost, 
three  solid  cant  ttmbera  of  American  elm  are  fitt«d  on  each  side, 
and  the  remaining  timbers  which  cannot  be  worked  in  one  length 
across  the  middle-line  should  be  well  rnnnected  to  the  s'liwl^ 
and  have  their  heeb  checked  int<j  and  secured  to  the  dead-woods, 

Ganwale.— Of  American  rock  elm,  about  4°  X  Ij",  and  is 
usually  fitted  in  two  pieces  in  the  length  of  boat,  well  scarphed 
together  at  one  of  the  transverse  bulkheads,  sr>  that  tiic  tatter 

•becomes  a  means  of  support  to  the  scarph.     The  scarpbs  are 
shifted  clear  of  the  same  bulkhead. 
Galvanised    wrought-imn    breasthooks.    with   deep    throats, 
are  fitted  at  the  aprons  and  ends  of  the  gunwales,  bolted  with 
nuts  ajifl  screws,  the  nuts  being  on  the  iron  breasthooks. 

Covering-Board,— A  covering-board  of  oak  or  American 
elm,  1  in,  in  thickness,  is  fitted  above  the  gimwale,  as  shown  in 
Figs.  11.")  and  116.  This  forms  a  protecting  strip  to  the  deck 
ends  or  hatch  covers  over  the  buoyancy  tanks. 

Web  Beams  and  Lower  Thwarts,— About  four  in  number 
lower  thwarts  are  fitted  between  the  end  transverse  bulkheads, 
for  the  full  breadth  of  tlie  boat  from  gunwale  U}  gimwale.  Thev 
are  made  from  pitch  or  red  pine  about  9  in,  in  breadth,  IJ  in.  in 
thickness,  and  well  secured  with  screws  to  the  gunwale,  longi- 
tudintil,  and  transverse  bulkheads.  These  thwarts  are  only  used 
for  the  purpose  of  seating  and  not  for  rowing, 

Web  beams,  C  X  IJ",  are  fitted  in  diagonal  fashion  at  the 
ends  of  the  boat,  notched  into  and  secured  to  the  transverse 
lifting  biilkbead  and  gimwale.  These  beams  stiffen  up  the  ends 
and  support  tlie  connections  through  the  end  combinations. 

t    Short  beams  of  oak  or  American  elm  are  worked  between 
nd    notch«l    into   the   gunwale   and    longitudinal    bulkheads. 


208  SHIPS'  BOATS  H 

about  Ij"  X  IJ",  spaced  about  9  in.  apart,  centre  to  centr^ 
These  are  well  secured  to  the  portable  hat<:hes  which  cover  the 
buoyancy  tanks. 

Hatch  Covers. — These  are  fitted  over  the  buoyancy  tank 
spaces  and  the  compartments  at  tlie  ends  of  the  boat.  The 
edges  of  the  covering  board  and  thwarte  are  rabbeted  to  receive 
the  covers.  A  flush  upper  surface  is  tlius  preserved  fore  and 
aft  over  the  buoyancy  tauks.  The  covers  are  usually  made  from 
pitch  pine,  feather  and  grooved,  and  secured  to  the  short  portable 
beams. 

To  provide  suitable  means  of  inspecting  the  interior  of  the 
boat  and  to  allow  the  buoyancy  tanks  to  be  removed,  the  hatches 
are  secured  to  the  longitudinal  bulkheads,  thwarts,  and  covering 
board,  by  strong  brass  screws  fitted  in  cup  sockets. 

The  "  deck  "  ends  are  permanently  secured  to  the  hull,  but 
a  portable  hatch  is  fitted  at  each  end  in  a  similar  way  to  the 
hatches  over  the  buoyancy  tanks,  for  the  purpose  of  inspecting 
the  condition  of  the  hull. 

The  thickness  of  the  hatch  covers  is  not  less  than  1  in. 

Planking, — One  of  the  most  important  features  in  the  con- 
struction of  this  type  of  boat  is  the  efGciency  of  the  planking. 
Sufficient  reason  has  already  been  given  for  expressing  the 
opinion  that  the  material  of  the  planks  should  be  mahogany — 
either  Honduras  or  Laj^os.  Gaboon  mahogany  must  be  avoided 
as  it  is  deficient  in  strength  and  lasting  qualities.  It  is  somewhat 
difficidt  at  times  to  discover  the  difference  between  the  three 
species  when  they  are  apart.  Gaboon  is  much  lighter  in  colour 
and  weight  than  any  other  species  of  mahogany. 

As  soon  as  tlie  skeleton  frame  of  the  boat  is  secured  together, 
it  is  usual  to  turn  the  boat  upside  down  to  facilitate  the  work  of 
planking. 

Two  thicknesses  of  material  are  used,  each  about  ^  of  an 
inch,  making  a  total  thickness  of  |  of  an  inch.  The  strokes  are 
4  in.  in  breadth  and  worked  fore  and  aft,  the  outer  skin  strakes 
breaking  joint  witli  those  of  the  inner.  The  inner  thickness  is 
completed  before  action  is  taken  to  commence  working  the  outer. 
The  inner  thickness  is  secured  to  the  timbers  with  wrought  copper 
naib,  12  B.W.G.,  clenched  on  rooves  of  substantial  section. 

Before  the  outer  skin  is  worked,  a  ply  of  calico  is  laid  in 
white-lead  on  (he  surface  of  the  inner  skin. 

The  outer  skin  nuist  be  carefully  worked  to  prevent  "  puffing 
off  "  between  the  two  thicknesses,  and  is  secm'«l  alon;,'  the  seanis 
to  the  inner  skin,  with  copper  nails,  13  B.W.G.,  clenched  ove 


I 


CONSTRUCTION  OF  CLASS  lU  OPEN  LIFEBOATS    209 

I  roovea  and  Hpacal  not  tijdre  than  2^  in.  apart.  The  diameter  of 
the  looves  is  not  less  than  g  of  aii  iiicli.  The  outer  and  inner 
skins  are  secured  to  the  timbers  by  copper  nails,  12  B.W.G., 
clenched  over  looves,  and  also  to  each  longitudinal  and  transverse 
bulkhead,  with  brass  screws  1^  in.  in  length,  spaced  6  in.  fore 
.  ftnd  aft  and  two  In  each  plank  athwart«hip. 

The  hood-ends  are  secured  to  the  aprons  and  deadwuod,  with 
'  brass  screws  at  the  caulking  edge  and  with  a  second  inner  row 
of  copper  nails. 

The  butts  are  carefully  arranged  to  secure  a  proper  shift 
1  in  the  inner  and  outer  thicknesses,  and  the  faying  suiiaces  are 
T  well  coated  with  thick  white-lead  paint  before  being  secured  with 
I  a  double  row  of  clenched  copper  nails. 

The  edges  of  the  garboard  atrakea  are  secured  to  the  hog- 
I  piece. 

The  number  of  fastenings  in   the   planking   make   it   very 
'  necessary  for  the  whole  of  the  securities  to  be  carefully  prepared 
by  drilling  tlie  holes  with  a  bitt,  and  easing  the  planks  without 
force  when  bending  them  towards  the  ends  of  the  boat. 

The  whole  of  the  seams  and  hood-ends  of  the  outer  thickness 
are  lightly  caulked  with  cotton  thread,  care  being  exercised  to 
prevent  the  sharp  edge  of  the  caulking  tool  from  cutting  the 
cotton  fabric. 

The  seams,  etc.,  are  then  filled  with  the  best  white-lead  putty. 

Uftfng    SUng    Arrangement. — The   lifting   bulkheads   at   the 

ends  of  the  boat  are  fitted  with  forged  eye-platea  of  the  design 

i  shown  in  Fig.   115,  liavin;;  V-shaped  securing  legs  and  so 

I  fitted  that  one  leg  is  placed  at  right  angles  to  the  pull  of  the 
aling-hook,  and  through  bolted  to  the  athwartship  lifting  bulk- 
head. The  other  leg  of  the  eye  plate  is  placed  in  a  vertical 
direction  and  secured  to  the  lifting  bulkhead  and  to  the  angle  bar 
which  also  connects  with  the  longitudinal  bulkheads,  thus 
providing  a  fair  distribution  of  the  stresses  between  the  principal 
combinations  in  the  frame  of  the  boat,  when  lifted  by  the  davits. 
The  arrangement  of  the  slings  is  governed  by  the  type  and 
position  of  the  davits. 

Buoyancy  Air-Cases. — These  are  fitted  along  the  sides  between 
the  longitudinal  bulkheads  and  the  planking.  They  are  made  of 
yellow  metal  or  copper,  not  leiss  than  18  ozs.  per  square  foot, 
and  made  suitable  in  size  to  bo  easily  removed  between  the  lower 

I  thwarts.     If  over  three  feet  in  length  they  should  be  fitted  with 
on   internal   bulkhead.     The    volume   is   1'5  cub.  ft.  Jor   each 
person  Khich  the  boat  ie  able  to  accommodate, 
L 


i 


198  SfflPS'  BOATS 

edge  amidships  is  a  few  inches  above  the  load  water-line  of  the 
boat.  They  are  made  portable  by  fitting  upper  and  lower  strips 
of  wood  to  act  as  a  bearing  for  securing  thereto  the  external 
buoyancy.  These  battens  are  about  2^^  X  1^^  and  secured  to 
the  timbers  by  clenched  fastenings ;  they  usually  take  the  run 
of  the  plank  kndings.  '  - 

Galvanised  iron  straps  about  3^  X  J^  with  strong  hinges 
at  the  top  and  bottom,  and  spaced  not  more  than  2  ft.  6  in.,  are 
arranged  to  support  the  several  lengths  of  cork  combination. 
In  way  of  the  butts  the  breadth  of  the  straps  is  slightly  increased 
to  provide  sufficient  bearing  for  the  two  ends.  The  edges  ot 
the  iron  straps  are  well  rounded  to  prevent  damage  to  the  canvas 
and  cork. 

The  upper  and  lower  battens  provide  an  air  space  between 
the  planking  and  the  external  buoyancy.  The  hinges  attached 
to  the  straps  are  secured  to  the  battens  by  three  sclrews,  care 
being  exercised  that  they  do  not  pierce  the  planking.  The  pins 
in  the  hinges  should  be  made  of  metal. 

The  two  end  lengths  are  slightly  tapered ;  and  to  prevent 
damage  to  the  cork  when  bringing  the  boat  alongside  a  jetty  or 
accommodation  ladder,  wooden  sliver  pieces  are  secured  to  the 
planking,  as  shown  in  Fig.  132. 

The  usual  procediu*e  is  for  the  boatbuilder  to  fit  the  battens 
and  secure  them  in  position,  make  the  backboard  to  suit,  prepare 
the  diaphragm  sections  and  secure  them  to  the  backboard.  Wood 
sections  are  forwarded  to  the  smith  to  enable  him  to  prepare  the 
iron  straps  and  hinges.  The  backboard,  etc.,  is  then  given  to 
the  sailmaker  or  a  maker  of  life-jackets,  who  prepares  the  cork 
slabs,  secures  them  to  the  backboard,  and  covers  the  whole  with 
the  approved  type  of  canvas. 

The  quality  of  the  cork,  etc..  should  be  inspected  before  it  is 
covered  with  the  canvas. 

In  cases  where  the  stability  of  boats  has  been  found  to  be 
deficient,  and  in  order  to  increase  the  moment  of  inertia  of  the 
water  plane,  the  fitting  of  cork  outside  buoyancy  has  often  been 
resorted  to. 

It  is  important  to  remember  in  arranging  the  overhang  of  the 
davits  that  accoimt  must  be  taken  of  the  additional  breadth 
given  by  the  outside  buoyancy  attached  to  a  Class  Ib  lifeboat. 
The  recognised  breadth  of  the  boat  is  the  greatest  breadth  to 
outside  of  planking,  and  not  to  the  outside  of  external  buoyancy. 
The  diameter  of  davits  carrying  this  type  of  boat  is,  therefore, 
larger  than  a  davit  under  which  is  stowed  a  lifeboat  of  Class  Ia, 


I 
I 


CONSTKUCTION   OF  CLASS  III.   BOATS         199 

on  account  of  the  greater  outreach  necessitated  by  the  fitting  of 
I  external  buoyancy. 


SECTION  C.-^ONSTIIUCTION  OF  CLASS  HI.  BOATS 

The  midship  section  of  a  Class  III.  boat  is  ilhistrated  in  Ftg.  7. 
This  type  of  boat  is  constructed  in  a  similar  way  to  an  open 
lifeboat  of  Class  Ia,  with  this  exception,  that  buoyancy  air-cases 
are  not  fitted. 

The  construction  is  praoticaUy  confined  to  the  "  clinker  " 
method.  They  very  rarely  exceed  22  ft,  in  length :  in  reality  they 
are  light  pulling  boat«,  and  it  is  quite  probable  they  are  used 
with  greater  frequeuc)'  than  the  larger  lifeboats  carried  on 
board  a  cargo  vessel. 

Passenger  vessels  are  not  permitted  to  carry  boats  of  Class  111. 
In  a  foreign-going  steamship,  not  certified  to  carry  more  than 
twelve  paasei^ers,  and  certain  other  vessels  mentioned  in 
Section  A,  Part  II.,  a  proportion  of  the  total  number  of  boats  to  be 
carried  may  be  of  Class  III.  As  an  example,  in  the  case  of  the 
foreign-going  steamship  referred  to,  if  the  total  number  of  lifeboats 
required  by  the  Life-saving  Appliances  Kules  exceeds  two,  a  boat 
of  Class  III.  may  be  carried  in  lieu  of  one  of  them,  and  if  the 
number  exceeds  three,  one  or  two  boats  of  Class  III.  may  be 
carried  in  hen  of  the  same  number  of  lifeboats.  The  Class  III. 
boats  as  well  as  the  Class  I.  lifeboats,  should  be  attached  to  davits. 
It  is  important  to  remember  that  when  a  vessel  is  certified  to 
carry  a  number  of  passengers,  not  eaxeedituf  twelve,  and  which, 
if  it  were  not  certified  to  carry  pasBengera,  would  be  subject 
to  rules  governing  foreign-going  steamsiiipa  not  certified  to  carry 
passengers,  nr  a  steamship  trading  within  home  trade  limits,  but 
not  certified  to  carry  passengers,  as  the  case  may  be,  it  is  subject 
to  the  rules  governing  the  boats  for  the  latter  cJasses,  and  not  to 
those  in  any  other  class.  Under  these  conditions  a  certain 
number  of  Class  III.  boats  may  be  carried,  but  steamships  certified 
to  carry  more  than  twelve  passengers,  must  have  buoyancy  air-casea 
fitted  to  the  whole  of  the  open  lifeboats  carried  on  board. 

Every  boat  which  is  carried  on  board  a  vessel  is  classified, 
provided  that  it  forms  a  part  of  the  statutory  equipment  of  the 
vessel.  Boats  which  are  carried  in  addition  to  the  equipment, 
such  as  working  boats  or  the  captain's  dinghy,  need  not  be 
classified. 

Class  III.  boats  must,  therefore,  be  built  under  inspection, 


212  SHIPS*  BOATS 

Stowing  Chocks. — Three  good  solid  stowing  chocks  and  cover 
bearers  are  secured  t^)  eacJi  of  the  solid  bulw^arks  immediately 
over  th(^  wing  bulkheads,  so  that  when  the  bulwarks  are  hinged 
down  into  their  stowhig  positions,  some  substantial  support,  is 
obtained  from  the  longitudinal  and  transverse  bulkheads. 

These  chocks  are  so  formed  that  when  the  keel  of  the  upper 
boat  is  stowed  on  the  khigplank  of  the  boat  below,  the  bilges  of 
th(»  upper  boat  are  resting  in  the  chocks. 

Griping  Bars. — ^Two  galvimised  iron  griping  bars,  constructed 
so  that  the  gripes  are  clear  of  the  corkf  ender,  are  supplied  with 
each  boat  to  enable  the  latter  to  be  well  secured  in  position  on 
tlio  deck. 

General  Instructions. — The  whole  of  the  timber  used  in  the 
construction  of  these  boats  must  be  of  first-rate  quality  and  well 
seasoned.  All  ironwork,  including  iron  bolts  and  washers,  are 
heavily  galvanised.  The  boats  are  constructed  under  the 
inspection  of  a  ship  surveyor  of  the  Board  of  Trade. 

Before  construction  is  commenced,  a  detailed  specification 
has  to  be  submitted  to,  and  approved  by  the  Board  of  Trade, 
who  also  demand  certain  tests  to  be  carried  out,  to  which  reference 
will  be  made  later. 

Modifled  Class  IIa  Open  Lifeboat. — Since  the  issue  of  the 
Report  from  the  Conmiittee  on  Boats  and  Davits,  and  the 
International  Convention  Regulations,  the  minds  of  boatbuilders 
have  been  stimulated,  and  attention  devoted,  to  the  necessity  of 
providing  a  better  protection  to  the  occupants  of  the  boat  than 
that  given  by  the  canvas  bulwarks  fitted  at  the  ends. 

The  *'  all  wood  "  type  of  collapsible  bulwark  has  thus  been 
brought  into  existence  by  one  or  two  well-known  firms  on  the 
Clyde,  and  is  consiilered  to  be  a  more  reliable  method  of  keeping 
out  the  water,  offers  a  better  protection  to  the  occupants  of  the 
boat,  and  is  moie  serviceable  and  durable  than  the  old  arrange- 
ments provided  in  the  standard  t\T)e. 

The  outside  buoyancy  has  been  dispensed  with,  and  a  rope 
fender  litted  in  lieu.  Two  cross  bulkheads  have  been  deleted  to 
allow  wounded  persons  to  be  placed  in  the  well. 

To  compensate  for  these  modifications  the  internal  buoyancy 
provided  by  the  watertiglit  air-cfises  has  been  increased  in  volume 
from  1*5  to  1"7  cub.  ft.  for  each  person  accommodated  in  the 
boat.  The  minimum  freel)()ard  of  the  loaded  boat  is  not  to  be  less 
than  that  laid  down  in  the  L.S.A.  Rules  for  the  standard  boat 
but  increased  by  15  per  cent. 

A  coir  rope  fender,  not  less  than  4  in.,  made  up  of  long 


feTRUCTION  OF  CLASS  IIa  OPEN  LIFEBOATS    273 

stranda,  unlaid  but  marled  to  the  diameter,  is  fitted  round  the 
boat  in  lieu  ot  the  external  cork  bunyancy.  An  air-space  between 
the  fender  and  the  boat  planking  is  arranged,  to  preserve  the 
latter  from  the  effects  of  rot.  The  general  arrangemejit  of  this 
fender  ia  shown  in  Fig.  95. 

The  hidk  of  boats  of  thia  class  are  practically  standardised 
according  to  the  specification  approved  by  the  Board  of  Trade, 
but  there  are  differences  in  the  type  and  general  arrangement  of 
the  bulwarks. 

In  the  interests  of  the  various  boatbuildera  who  have  brought 


I 


out  patent  details  in  (Tinnection  with  this  class  of  boat,  the  writer 
hsB  purposely  refraineil  from  any  minute  description,  but  illus- 
trations are  given  which  give  a  general  idea  of  the  construction. 
Fig.  117  shows  the  patent  modified  Class  IIa  open  lifeboat 
constructed  by  Messrs.  Hugh  Mcl^ean  and  Ron,  of  Govan,  and  the 
various  details  illustrated  in  Fig.  116  indicate  hiiw  the  bidwarks 
are  constructed  and  made  watertight. 

The  horizontal  and  vertical  joints  are  made  watertight  by 
rubber  jointing,  f  X  |1.*,  or  lamp  wick,  the  foi-mer  being  secured 
to  the  coamings  by  solution  and  |-in.  brass  screws  6  in.  apart. 
'  The  bulwark  ends  consist  of  three  pieces  hinged  together  on 


314 


SHirS"   BOATS 


the  nutBide,  so  that  the  eD<l  pieces  fold  over  un  the  centre  piec 
and  collapse  with  it. 

Doors  are  fitted  at  the  sides  to  enable  peit^ms  struggling  i 
tliB  water  to  he  Htted  over  the  deck  in3ti?<ad  of  over  the  frunwal 
[)!'  Iiulwark. 

All  the  vertical  joints  are  efEciently  held  with  wedgea  i 
hawd  clips. 

The  whole  of  the  arrau^emeiibs  are  tn'eatly  in  advance  of  tM 
tyi)e  nf  boat  having  canvas  bulwarks.     The  bulwarks  i 
the  great  advantage  of  having  tapered  ends  for  thmwing  < 
the  water. 

Messrs.  Gouk  and  Nesbit,  of  Glasgow,  have  patented  anotlM 
type   Claas   IIa  lifeboat,   which   difTers  slightly   from   the  oq| 
previously  descrjbeil,  the  general   view  of  the  boat,  with  I 
bulwarks  erected  in  place,  being  piven  in  Fig.  118.     The  i 
will  notice  the  difference  in  the  rowing  thwarts  to  thrwe  alrei 
(lewiibcd  in  the  general  sperification,  and  also  the  ]iatent  locki 
arrangements  on  the  aides.    The  portable  wooden  end  seats,  w " 
slipped  into  position,  prevent  the  hnlwark  ends  fnim  eollapsiiig.  ] 

The  time  taken  to  expand  the  boat,  erect  the  bulwarks,  aai 
place  the  end  seats  in  position,  was  recorded  as  15  8ecoads. 

The  special  feature  of  the  design  associated  with  the 
"  Hercules  "  patent,  constructed  by  The  British  Marine  Motot 
and  Launch  (^o.^  Ltd.,  Whiteinch,  Glasgow,  is  unique  and  orj^^ina]. 
There  are  the  usual  hinged  st<?m-piecea,  and  folding  bulwark 
in  the  straight- sided  portion  nf  the  boat,  the  latter  being  well- 
constructed  of  oak  and  mahogany  in  two  thicknesses.  Ui  the 
tnidflhip  bulwark  a  recess  is  so  arranse<l  to  receive  a  slidinj; 
portion.  These  movable  or  sliding  end  bulwarks  are  niado  on 
very  similar  lines  to  the  principle  of  the  "  roll-top  "  desk,  and  are 
composed  of  vertical  wooden  battens  of  two  thicknesses,  with 
canvas  laid  in  paint  between,  suitably  bound  tflgether.  By  the 
use  of  channel  irons  on  tJie  coaming  and  upper  gunwale,  which 
are  raised  into  position  when  erecting  the  thwarts,  and  form  a 
guide  for  the  sliding  portion  to  operate  in,  the  end  bulwarks  arc 
pulled  quickly  into  position. 

When  tlic  end  bulwarks  are  not  in  use  tliey  are  not  expo3<>d  to 
the  weather,  but  slide  into  the  recess  of  the  strai<;ht-sided  bulwark, 
and  hinge  down  into  the  final  stowing  position  witli  the  latt«r. 

The  thwarts  and  seats  are  supported  by  stanchions  which  arc 
connected  with  a  sliding  strap,  providing  a  mean.'*  whereby  the 
former  are  locked  or  imlocked  simultaneously.  The  whole 
arrangement  of  the  hinging;  of  the  upper  structure  i«  automatic  in 


CONSTRUCTION  OF  CLASS  IIa  OPEN  LIFEBOATS    215 


action,  the  simple  method  of  raisin^^  or  lowering  the  thwaria, 
locking  or  imlocking  them  as  the  case'may  be. 


i 


i 


216 


SHIPS'  BOATS 


Fig.  119  shows  the  side  bulwark  in  position  with  tli^te 

raised,  and  having  the  thwarts  and  seate  stiU  in  their  stowing^ 
positiim. 

fig.  120  indicates  the  channel  irons,  or  guide  bats,  in  position,, 
with  the  seats  and  thwarts  raised.  One  sliding  end  shutter  i: 
place  and  the  other  in  its  stowing  position  within  the  midshipl 
bulwark,  readv  to  be  drawn  out  into  ita  connection  with  the  steni(T 


Existing  types  of  lifeboats  of  Class  IIa  having  canvas  bulwarH^ 
can  be  fitted  with  the  new  wooden  bulwarks  as  previoosln 
described.  A 

It  is  a  misnomer  to  refer  to  this  class  of  boat  as  a  "  collapsible  '1 
lifeboat,  for  it  may  be  confused  with  the  Beithon  type  of  canran 
and  wood  boat,  which  is  purely  a  collapsible  boat,  and  largdr 
adopted  by  the  Admiralty  where  space  and  accommodation  will 
not_allow  ordinary  pidling  boats  to  be  stowed.  The  Class  Ua 
open  lifeboat,  and  Classes  lo,  IIb,  and  lie  pontoon  lifeboata  hav 


CONSTRUCTION  OF  CLASS  IIa  OPEN  LIFEBOATS    217 

rigid  and  substantially  built  hulls,  whose  upper  bulwarks  and 
thwarts  fonn  the  only  details  of  the  structure  which  collapse. 

Whatever  type  or  special  patent  boat  of  Class  IIa  or  pontoon 
lifeboat  is  carried  on  a  passentrer  vessel,  it  is  absolutely  essential 
for  them  to  be  carefully  watched  and  periodically  inspected, 
otherwise  they  will  fail  in  their  purpose  when  required  in  a  time 
of  difficulty  or  danger. 

There  is  an  important  feature  in  connection  with  the  con- 
struction of  this  and  other  special  desi^ms  of  lifeboats.  When  a 
boatbuilder  commences  to  build  a  new  type  of  boat,  in  addition 
to  submitting  a  detailed  specification  to  the  Board  of  Trade,  it  is 
necessary  for  him  to  carry  out  an  extensive  series  of  tests  before 
the  design  can  be  accepted.  The  writer  is  indebted  to  Mr.  Hugh 
McLean  for  the  record  of  tests  carried  out  under  Board  of  Trade 
supervision,  on  some  boats  constructed  at  the  Govan  yard. 

Surfaee  Measurement. — Before  dealing  with  these  tests  it  will 
be  well  to  make  reference  to  the  Life-saving  Appliances  Rules, 
which  state  that  the  number  of  persons  which  a  lifeboat  of  this 
class  shall  be  deemed  fit  to  carry,  shall  be  equal  to  the  greatest 
whole  number  obtained  by  dividing  the  surface  of  the  boat  in 
square  feet,  by  the  standard  unit  of  surface. 

The  standard  unit  of  surface  for  a  Class  IIa  lifeboat  is  3J 
sq.  ft. 

The  surface  in  square  feet  is  determined  by  the  following 
formula : — 

Area  =•  '  (2a  +  l'%  +  4o  +  I'Srf  +  2^) 

I  denotes  the  length  in  feet  from  the  intersection  of  the  outside  of 
the  planking  with  the  stem  to  tlie  corre^sponding  point  at  the 
stempost ;  a,  6,  c,  d  and  e  denote  tlie  horizontal  breadths  in  feet 
outside  the  planking  at  the  points  obtained  by  dividing  I  into 
four  equal  parts  and  sub-dividing  the  foremost  and  aftermost 
parts  into  two  equal  paits  {a  and  e  being  the  breadths  at  the 
extreme  sub-divisions,  c  at  the  middle  point  of  the  length,  and  h 
and  d  at  the  intermediate  points).  Keferencc  should  be  made  to 
Fig.  126. 

Freeboard  — The  minimum  freebc^ard  of  boats  of  Class  IIa 
is  fixed  in  relation  to  their  length.  It  is  measured  vertically  to 
the  top  of  the  solid  hull  at  the  side  amidships  from  the  water-level, 
when  the  boat  is  loaded. 

The  freeboard  in  fresh  wafer  shall  not  be  less  than  the  following 
amounts : — 


218  SfflPS*  BOATS 

Length  of  the  boat  Minimum  freeboard  in  inoHee. 

in  feet.  Class  IIa.  .  Modified  Class  IIa. 

26  8-0  9-2   =3   9^/ 

27  8-5  9-78  =   9i^ 

28  90  10-35  =  lOp 

29  9-5  10-93  =  10^^ 

30  100  11-5    =lli^ 

The  freeboard  of  intermediate  lengths  is  found  by  interpolation. 

Tests. — Before  construction  is  commenced  on  lifeboat^  of  this 
class  the  detailed  specification  must  receive  the  approval  of  the 
Board  of  Trade,  and  certain  tests  must  be  carried  out  before  the 
boats  can  be  accepted  and  allowed  on  board  a  vessel  as  part  of 
the  statutory  equipment. 

The  following  results  of  tests  on  a  Class  IIa  open  lifeboat  were 
supplied  to  the  writer  by  Messrs.  Hugh  McLean  and  Son,  and  will 
give  the  reader  a  good  idea  of  the  modus  operatidi  in  carrying  out 
a  series  of  te^ts. 

The  dimensions  of  the  sample  boat  were  : 

30  r  X91'X  r  llJ^(l-94') 

The  deck  arexi  was  obtained  in  accordance  with  the  requirements 
of  the  L.8.A.  Rules,  and  the  ordinates  taken  at  the  positions 
shown  in  Fig.  120. 

Onlinates.        Multipliers.  Functions. 

Stem   ....  00  0-5  0*0 

a 7-2  20  14-4 

h 90  1-5  13-5 

c 91  40  36-4 

d <)0  1-5  13-5 

e 73  20  14-6 

Stonipost       .      .  00  0-5  0*0 

]•>"'    12   ~^-"^  2'^'l 

231-924  sq.  ft. 

Capacity  of  iiit(»nial  buoyancy  tfinks  =>  87*57  cub.  ft. 
Volume  of  cxtcrual  buoyancy  =  11*6  „ 

Nuni])or  of  piMsoiLs  ol)tainod  from  )      232 
dock  area  j  "^  3-5  "^ 

Number  of  persons  obtained  from  (  ^87*57 -^ 

internal  hiioyaiicy  j   "    p5       ' 

Number  of  persons  obtained  ironi)_ll*6      ^^ 
ext(»rnal  buoyancy  (  ~~  0*2  ^^ 


CONSTRUCTION  OF  CLASS  IIa  OPEN  XIFEBOATS    219 


STRENGTH   TEST. 

The  boat  was  attached  to  a  spar  and  lifted  by  a  crane  to  enable 
the  stresses  to  operate  on  the  hnll  under  service  conditiona. 
Sights  were  fixed  to  the  stem,  sternpost,  and  centre  thwart. 

(a)  Boat  light. — Sights  were  adjusted  while  the  boat  was  on 
the  quayside  on  level  ground.  The  boat  was  then  lifted  by 
the  crane : — 

Deflection  measured  =^  j-'jr  in. 
Permanent  set  —  nil. 

(b)  Boat  loaded  with  weights  equal  to  54  persons  and  equipment 
(number  of  persons  obtained  from  a  previous  freeboard  test) : — 

54  persons  at  1(55  lbs.  -  795  cwts. 
Equipment  —    50 

Total  load  -:  84-5 
Deflection  measured  and  found  to  be  -J  in. 


»» 


>» 


S/tffr 


S^SAfT 


Fia.  121.  -  -Strongth  kst  of  Class  IIa  liff})()at. 

(c)  Boat  loaded.  Plm  25  }H>r  r^w/.— The  boat  was  then  loaded 
with  weights  equal  to  54  persons,  equipment,  and  an  addition 
of  25  per  cent,  of  the  full  load. 

54  f)ersons  at  1()5  lbs.  —  79-5  cwts. 

E(juipnient   -     5*0     ,, 
Actual  weight  of  boat  -    38-5     ,, 

123(>     ,. 
Plus  25^;,-   30-8 

15.3.8 
Less  weight  of  boat  ■—    ^t^Ty 

Tost  load  ^-  115-0 

Deflection  measured  and  found  io  be  ] ;'!  in. 

(d)  Boai  light. — All  the  weights  wore  discharged,  boat  landed 
on  level  ground,  sights  adjusted,  and  permam^nt  set  was  found 
to  be  nil.     (See  Fig.  121.) 


>> 


»> 


>» 


5' 


220 


SHIPS'  BOATS 


FREEBOARD   TEST. 

(a)  Boat  lowered  into  water  (partially  salt)  and  freeboard 
examined  amidships.     (See  Fi^'.  122.) 

Distance  between  water-level  and  top  )  _^  ^  76^ 
of  Viilwark  ^niwale  *  )  ^ 

Distance  between  top  of  "  deck  "  and  1  _,  9'  1?^ 
top  of  bulwark  jninwale  ( 

—  m 

Freeboard  =  1'  5|^ 

(b)  The  specific  ^^ravitv  of  water  taken  from  the  dock,  at  a 
temperature  of  (iO"  F.  —  1017  oz<. 

Uul(*,  freeboard  for  30-ft.  Class  IIa  lifeboat  =  10  in. 
Freeboard  after  a<ljustinent  for  salt  water   =10J  in. 


Kks.      122  ¥jq.  123. 

Frc^eboard  iiiid  flottitiun  tcsUj  of  Class  Ha  lifeboat. 

Boat  while  afloat  was  loaded  with  wei^^hts  evenly  distributed 
in  order  to  maintain  a  level  keel,  until  a  freeboard  of  lOj  in.  was 
obtained  at  amidships.  (See  Fiir.  123.)  Weights  on  board  were 
then  recorded  as  follows  : — 

11)9  weiizhts  at  50  lbs.  each  =  84*5  cwts. 
Less  ecpiipment  =    5*0     „ 

79-5     „ 

7i)-r)  X  112 

1  g:) 


-  -  54  persons. 


Tlie  (leek  ariNi  was  suHici(Mit  for  (Hi  pers(ms.  Therefore  the  free- 
board, in  till  >  <'a  e.  is  tlie  ^overniniz  factor  which  settles  the  number 
of  persons  wiiicii  can  ho  assiirned  to  the  boat.  It  will  also  be  sieen 
tiiat  the  «'xt(Mnal  ami  internal  buoyancy  were  sufficient  for 
.58  person^.  If  [\w  deck  area  had  j^Mven  a  smaller  number  of 
persons  tlian  51,  thtMi  that  smaller  number  would  have  been  used 


CONSTRUCTION  OF  CLASS  11a  OPEN  LIFEBOATS    221 

for  the  assignment,  provided  there  was  sufficient  seating  accom- 
modation. 

FLOODING   TEST. 

(a)  Boat  was  floated  in  the  light  condition  and  without 
equipment.  Plugs  were  then  withdrawn  and  the  boat  flooded 
with  water  imtil  the  water  inside  was  at  the  same  level  as  outside. 

Freeboard  measured  amidships  =  11^  in. 

(b)  Boat  remained  in  condition  (a),  but  with  plugs  inserted. 
It  was  then  loaded  to  the  condition  when  the  top  of  the  air- 
cases  was  awash,  i.e.  with  a  freeboard  of  IJ  in. 

The  load  on  board  was  111  cwts.,  and  allowing  5  cwts.  for 
equipmen^- 

This  would  equal  — -  -  - —  =3  72  persons. 

(c)  The  weights  were  removed.  Plugs  were  again  withdrawn, 
and  sufficient  weights  added  to  bring  the  top  of  the  air-cases 
awash  inside  and  outside  of  boat,  i.e.  possessing  a  freeboard  of 
IJ  in.,  and  the  inside  of  the  boat  was  filled  with  water  to  the 
same  level  as  outside. 

The  load  on  board  was  56  cwts.,  and  allowing  5  cwts.  for 
equipment — 

This  would  equal  -      _  j.      =>  34  persons. 

STABILITY    TEST. 

It  was  estimated  that  38  persons  could  be  accommodated  on 
the  permanent  structure  and  the  remaining  16  persons  on  the 
upper  thwarts. 

The  centre  of  gravity  of  54  persons  above  the  "  deck  "  was 
estimated  as  follows  : — 

38  persons  at  10  ft.  above  deck  =  moment  of  38 
16        „         2-25         „        „    =       „         „36 

54  74 

C.6.  of  persons      '^^  __  i  .07  tf 
above  deck     "^54 

54  persons  =>  79*5  cwts.     Equipment  =  5  cwts. 
Total  load  =»  84*5  cwts. 

Timber  support  was  erected  in  the  boat  for  the  accommodation 
of  the  weights  (representing  persons)  which  were  arranged  as 
follows : — 


222 


SHIPS'  BOATS 


60     cwts.  at  1'4:  ft.abovedeck=  84"0  moment 
13  „      1-3  ft.      „      „    =  16-9 

Staging  (55  cwts.)  at  lift.      ,,      „    =    6*05 
4  men  (6   cwts.)  at  1-2  ft.      „      „    =    7-2 


99 
99 


Total  weight  =.84-5    „ 


Total  moment  =  114'15 


11415 
Position  of  G.6.  of  load  =  -  --     =  1*35  ft.  above  deck. 

84-5 

(a)  Boat  in  service  condition,  weights  arranged  as  already 
described  (see  Figs.  21,  124  and  125),  and  so  placed  that  the 
upper  weights  could  be  readily  moved  from  one  side  of  the  boat 
to  the  other. 

A  measurement  batten  was  prepared  as  shown  in  Fig.  124. 


-nrrrrr 


_,j    ^- 


:.^'-^ 


Fia.  124. 


Fia.  126. 


Stability  tctits  of  Class  IIa  lifeboat. 

indicating  the  readings  from  the  top  of  the  bulwark  gunwale, 
marked  in  feet  and  inches. 

Distance  between  reading  edges  of  scale  =  10'  5J^ 

Transverse  shift  of  weights  =    T  2" 

Tlie  readings  from  the  various  inclinations  were  recorded  as 
follows  : — 

Initial  scale  readings  :  Vorl,  '21  WY  \  Starboard,  2'  11J\ 


Cwts.  *"'^'^^- 


Scale 
reudiu^. 
Port. 


*) 


/    i)/r 


r  2 


•»/  I  * 


3'  1 


:  Ditfereuco. 


11" 


Scalo 
reading. 
Starboard. 

Difference. 

Total. 

2'  lOJ' 

ir 

2|* 

The  inclinations  were  continued  until  the  deck  was  well  awash, 
and  the  readings  noted  as  detailed  above.  Two  or  four  men  are 
usually  left  in  the  boat  to  shift  the  weii^hts  in  a  transverse 
direction. 


CONSTRUCTION  OF  CLASS  IIa  OPEN  LIFEBOATS    223 

(b)  Boat  in  service  condition  as  at  (aj,  bvi  mlh  the  addition  of 
2  tons  of  tcUer  inside. — The  amount  of  water  to  be  placed  on 
board  was  previouflly  estimated  by  addiii;;  two  tons  of  weights 
on  board  and  retordini,'  the  diSerente  in  freeboard. 

The  weifihts  were  arran<;ed  exactly  in  the  positions  fixed  for 
the  first  test,  but  with  the  two  toua  of  free  water  on  board.  The 
readings,  after  inclination,  were  noted  and  placed  in  the  order 
arranged. 

From  the  information  thus  obtained,  atability  curves  could 
be  plotted  and  recorded. 

SEATING   AND    ROWING   TEST. 

The  boat  was  loaded  with  54  jiersons  we-aring  life-jacketa ; 
38  being  on  the  "  deck."  or  permanent  structure,  and  16  seated 
on  the  upper  or  collapsible  thwarts.  It  was  aftei-warda  rowed 
and  steered  about  the  dock  for  15  minutes.  The  boat  was  stable 
and  remained  in  correct  trim,  and  there  appeared  to  be  sufficient 
room  for  the  proper  seatinf!  of  the  total  number  of  persons  on 
board.  The  length  of  oars  was  13  feet,  four  in  number  each 
aide,  the  thwarts  being  double  banked. 

On  the  results  of  these  teats  depend  whether  the  boat  can  be 
accepted  for  service  on  a  vessel,  and  whether  the  constructian  on 
the  remaining  batch  of  boate  can  be  completed  without  any  further 
alterations. 

The  teste  entail  iinich  expense  and  a  great  deal  of  labour, 
whidi  could  be  obviated  if  standard  dimensions  and  details  of 
construction  were  recognised  and  made  compulsory. 

It  should  be  mentioned  that  with  the  modified  Class  IIa 
lifeboat,  account  has  to  be  taken  of  the  additional  freeboard 
required  over  the  staudai'd  boat.  Fiuther  tests  are  ahio  under- 
taken to  ascertain  if  the  end  and  side  wooden  bulwarks  are 
watertight  at  the  joints. 

SECTION  E.— t^0N«TRUCT10N  OF  CLASS  Ic,  11b  AND 
IIo  PONTOON  LIFEBOATS  WITH  COLLAPSIBLE 
BULWARKS 

The  differences  between  the  three  classes  of  lifeboats  now  under 
treatment  can  be  seen  in  Figs.  3,  ■')  and  C, 

Lifeboat**  of  Classes  lo  and  liw  are  identically  tlie  same  in 
method  of  constniction  and  general  design,  except  ia  regard  to 


224 


SHIPS'    BOATS 


the  bulwarks.  In  Class  Ic  lifeboats  the  bulwarks  are  fixed,  but 
in  Class  IIb  lifeboats  they  are  made  to  collapse  and  hinge  down 
on  the  deck  in  the  manner  described  for  Class  IIa  open  lifeboats. 


OUTSiOe  BOOYA/^CV 


Fig.  120. — "Deck"  plan  of  Clasa  IIa  oix-n  lifeboat. 


v.. 


COLLAf>S/BLA  aut.V¥A»ffS 


wcr  y^£LL     osCM 


l.W.L 


?\j>frf}n>/if\i: -y- - -'»«-^- — -r~^ff  f  f  f  '  *  ■'■fl 


—   ELEVATION  — 


Fkj.  127.  -Outline  of  "deck"  ami  well  of  Class  IIb  pontoon  lifeboat. 


•         COi-LAPSlBLE  THrfARTS  ^G_'^        ^ 


rtCfSM  ^'^-  ^'CH 


x--r — n — 


IS' 


Flu.  12S.  -Sccti'tn  of  Class  Uc  pontoon  lifeboat. 

Lifeboats  of  Class  Ic  do  not  lind  nmcli  favour  with  shipowners 
and  shipbuiklers,  owing  to  the  additional  room  required  for  the 
fixed  bulwarks,  and  as  deck  space  is  of  such  great  consideration 
in  a  passenger  vessel,  we  usually  find  that  Class  I.  open  lifeboats 


CONSTRUCTION  OF  PONTOON  LIFEBOATS      226 

eattacLed  to  all  the  davits,  and  the  additional  lifeboats  required 
0  make  up  the  full  complement  are  of  the  pontoon  or  open  type 
possessing  collapsible  bulwarks.  Boats  having  collapsible  bul- 
warks are  thus  able  to  stow  under  the  Class  I.  open  lifeboats 
attached  to  davits,  as  shown  in  Fig.  129,  or  may  be  stowed 
inboard,  one  above  the  other,  transporting  arrangements  being 
fitted  under  the  boats  to  bring  them  rapidly  under  the  davits. 
Fig.  226  and  the  frontispiece  show  how  the  pontoon  lifeboat-a 
are  stowed  inboard  and  adjacent  to  the  da\'it8. 

The  outstanding  difference  between  pont^>on  lifeboats  and  the 
open  lifeboats  of  Class  IIa  is  to  be  seen  in  the  method  of  providing 
the  reserve  of  buoyancy. 

Class  IIa  lifeboats  are  fitted  with  buoyancy  air-cases,  while 
pontoon  lifeboata  of  Classes  Ic,  IIb  and  IJc  depend  entirely  upon 
the  watertightness  of  their  hull  for  buoyancy.  Therefore  it  is 
very  essential  that  the  workmanship  and  materials  used  in  the 
construction  ot  the  pontoon  lifeboats  should  be  of  the  very  best 
quality. 

In  the  first  place,  the  timber  used  must  be  thoroughly  seasoneil, 
and  when  completed  and  in  service  on  board  a  vessel,  they  should 
be  periodically  and  very  carefully  inspected.  Every  compart- 
ment must  be  easily  accessible  and  ventilated  at  everj'  convenient 
opportunity. 

If  there  were  the  slightest  trace  of  dry  rot  in  the  hull  of  the 
boat  when  first  completed,  it  would  very  rapidly  spread  under 
the  conditions  of  a  close  atmosphere  after  the  compartments 
had  been  closed  in  by  the  watertight  deck. 

Reference  has  already  been  made  when  discussing  the  details 
of  construction  of  ordinary  pulling  boats  of  the  importance  of 
having  all  shavings  cleared  out  of  the  boat  before  and  after 
painting.  The  necessity  for  this  precaution  is  even  gieat«r  in 
the  case  of  pontoon  lifeboats,  owing  to  the  special  features  of 
their  construction.  Shavings  very  quickly  become  infected  with 
dry  rot  mycelium,  and  carry  the  disease  to  other  parta  of  the 
structure. 

The  watertight  deck  is  open  to  the  effects  of  the  weather,  and 
in  the  case  of  wooden  boats  the  latter  has  a  direct  influence  on 
the  value  of  the  deck  to  keep  out  water,  and  for  this  and  the  other 
reasons  mentioned,  it  is  essential  to  periodically  inspect  the 
interior  of  these  boats. 

The  difference  between  the  Class  IIb  and  Class  IIo  pontoon 
Bfi^oats  is  found  in  the  design  of  the  deck,  the  former  has  a 
H|vU "  deck  and  the  latter  has  a  fiush  deck.     The  skeleton 


CONSTRUCTION  OK  PONTOON  LIFEBOATS     227 

IfniQiea    of   theso    two    boats    are   practically    alike,   aiwl    tliey 

■do  not  greatly  differ  from  tlie  V\aj~s  IIa  lifeboats  in  this  respect, 

■Jtocept  tiiat  the  transverec  bulkheads  in  the  pontoon  lifeboata 

je  watertigbt.     It  ia  quite  passible  that  the  bulwarks  of  these 

mats  will  be  of  the  aU  trond  type  in  future  construction,  instead 

Rof  the  combined  use  of  wood  and  canvas.     Very  few  passenger 

ftVeaeela  were  completed  during  the  war  except  as  cargo-carrj-iog 

ibipe,  which  considerably  influenced  the  output  of  the  boats 

with  collapsible  bulwarks. 

The  hull  structure  of  a  pontoon  lifeboat  is  divided  into  a 
number  of  transverse  watertight  compartments,  bounded  by 
L  bulkheads  built  up  in  two  thicknesses  similar  to  the  outside 
planking,  and  strengthened  by  longitudinal  non- watertight 
ntlwatks.  The  size  of  these  watertight  compartments  are  so 
iranged  that  should  the  stnicture  become  damaged  with  two 
tompartmenta  laid  open  to  the  sea,  and  having  the  full  complement 
ii  peisoim  on  board,  there  would  still  be  a  reserve  of  buoyancy 
f^nd  sufiicient  stability  to  enable  the  boat  to  keep  afloat  without 
d&nj!ei  to  the  occupants. 

The  skin  or  planking  is  made  up  of  two  thicknesses  of  mahogany 
worked  in  diagonal  fashion,  and  the  planks  arc  fitted  from 
gunwale  to  gunwale  at  right  angles  to  one  another.  The  minim\im 
width  of  the  planks  is  6  in.,  and  between  the  two  thicknesses  is 
laid  a  covering  or  ply  of  stout  calico  and  white  lead-paint.  Before 
the  calico  is  worked  the  plank  is  treated  with  boiled  linseed  oil. 
An  alternative  preparation  for  the  fabric  is  No.  5  Navy  Canvas, 
]aid  in  liquid  marine  glue. 

These  tj-pes  of  boata  are  very  wide  and  shallow,  giving  a  full- 
formed  floor,  and  when  stoned  on  deck  and  secured  with  gripes 
there  ia  always  a  certain  amount  of  "  working  "  felt  at  the  con- 
nection of  the  plank  ends ;  the  action  of  a  se.away  would  have  the 
same  eSect.  To  obviate  le-akage  at  the  keel  seam,  and  to  main- 
tain an  unbroken  skin  to  each  compartment  of  the  hull,  the 
planks  are  fitted  from  gunwale  to  gunwale.  The  keel  and  bilge 
keelsons  are  fitted  after  the  planking  is  complete,  and  the 
keelsons  are  formed  with  the  usual  hand  grips  to  enable  persons 
to  cling  to  the  boat  should  it  capsize. 

"  Ltindln  •*  Lifeboats. — Messrs.  The  Welin  Marine  Equipment 
Co.,  Long  Island  City,  New  York  {now  American  Balsa  Company 
Iqc.)>  have  specialised  in  the  particular  type  of  boats  now 
under  leview.  The  London  firm  has  been  good  enough  to 
supply  the  writer  with  a  number  of  photographs  of  the  various 
desigoa  from  which  illustrations  have  been  produced. 


238  SHIPS'  BOATS 


I 


CONSTRUCTION  OF   PONTOON  LIFEBOATS     229 

Fig.  129  ahows  a  28-ft,  "  Lvndin  "  decked  lijeboat  stowed  under 
a  Class  I.  open  liJeboat,  These  boats  are  built  of  heavj-  galvanised 
steel,  double  riveted,  with  countersunk  tinned  tivete.  The  hull 
is  decked  in.  The  folding  bulwarks  are  of  substantial  constniction, 
and  when  raised  to  the  vertical  position,  automatically  lock  them- 
selves. Canvaa  bulwarlts  have  been  superseded  a3  being  liable 
to  perish  very  quickly.  The  collapsible  bulwarks  when  hinged 
down  into  the  stowing  position  form  a  good  foundation  to  stow  a 
second  boat. 

The  hull  is  sub-divided  into  transverse  watertight  compart- 
ments, with  raised  manholes,  providing  access  thereto,  The 
manhole  covers  are  held  in  place  by  "  poit-Iight  screws," 

Patent  non-return  valves  are  fitted  to  the  deck,  which  quickly 
discharge  water  coming  over  the  bulwark  and  prevent  water 
entering  fi-om  below. 

A  characteristic  feature  of  these  and  other  types  of  lifeboats 
built  by  the  firm,  is  the  use  of  a  very  light  fender,  which  adds 
stability  and  strength  to  the  boat.  The  wood  used  is  known  as 
Balsa  ivood,  which  Ls  hghter  than  ordinary  cork,  and  is  also 
utilised  in  the  manufacture  of  life-preservers,  lifebuoys,  and  rafts, 
and  complies  with  the  United  States  inspection  requirements. 
These  fenders  are  secured  in  place  by  metal  straps,  and  can  be 
removed  for  repair  or  painting  in  a  few  minutes. 

The  boats  are  of  tlie  scow  type,  having  a  spoon-shaped  bow 
and  stem  considerably  raised,  which  gives  them  a  great  riding 
advantage  in  rough  weather,  They  ofier  many  advantages  as  to 
seaworthiness,  carrying  capacity,  and  facility  of  stowage.  The 
United  States  Transport  Service,  and  many  leading  steamship 
lines,  have  adopted  this  particular  type  of  boat. 

Fig.  131  illustrates  the  Lundin  Housed  Lifeboat,  which  is  some- 
what similar  in  design  to  the  "  decked  "  lifeboat,  but  is  provided 
with  a  house  in  which  are  fitted  patent  port  hds  through  which 
oars-can  be  used  tor  the  purpose  of  propelling  the  boat.  Water- 
tight doors  completely  protect  the  passengers  from  bad  weather. 
Automatic  ventilators  are  fitted  to  the  house, 
W  Fig.  130  gives  a  general  view  of  the  "  Lundin  "  Power  Lifeboat, 
vbich  embodies  all  the  essential  features  necessary  for  this  type 
of  boat.  It  is  self-righting  and  self-baling.  The  propeller  is 
located  and  well  protected  in  a  tunnel.  The  boat  manceuvres 
■well  in  the  water,  and  can  be  carried  in  davits  ;  it  possesses  many 
advantages  over  the  ordinary  type  of  boat.  It  serves  the  purposo 
iof  "  mothering  "  the  other  lifeboats  in  case  of  necessity,  an 
Sluatfatioa  of  which  Is  giveu  in  Fig.  133. 


fic.  132. — '■  J.undiii  "  power  lifcbutil  imdcraaing 


..^  .1 


1,„?!!S'  }?  f'u'"'  "  f""""  li'ebMt  undergomR  a  stability  test,! 
bavmg  the  f„lj  a„„i,„  „(  p,^^  accommodated  witUn  tll> 


"     powi'r  lileboiit  tgwing  dock-'d  and  o|ion  li[ebo*ls. 


CONSTRUCTION  OF  PONTOON  LIFEBOATS     23l 

house,  and  a  ntimbec  of  men  standing  on  one  gunwale,  whicli 
indicates  the  large  amount  of  reserve  stability  poaseased  by 
tliia  type  of  boat,  and  hence  her  steadiness  for  the  passengers' 
comfort, 

Wireless  telegraphy  apparatus  completes  the  equipment  and 
enables  the  boat  to  keep  in  touch  with  vessels  and  secure  help 
quickly  in  case  of  need. 

While  those  boata  are  necessarily  somewhat  espeuaive  to  build, 
they  are  carefully  designed  with  a  view  to  niinimbe  trouble  and 
expense  of  upkeep. 


DECK    AREA    AND    CAPACITY    OF    PONTOON    BOATS. 
Classes  Ic,  lU  and  lie. 

The  method  of  obtaining  the  deck  area  is  exactly  the  same 
as  that  which  is  adopted  for  the  Class  IIa  boat,  explained  in 
Part  IV.,  Section  D.  and  illustrated  in  Figs.  12(5  and  127, 

The  Kni(  oj  surface  is  : 

Classes  Ic  and  IIb  ^  3|  sq.  ft. 
Class  lie  =  3J     „ 

To  obtain  the  number  of  persons  which  the  boat  will  carry,  as 
far  as  the  deck  area  will  allow,  we  take  the  superficial  area  calcu- 
lated in  accordance  with  the  approved  formula  and  divide  it  by 
the  correct  unit  of  capacity,  the  result  will  give  ua  the  number  of 
persons. 

Freeboard. — Boats  of  Classes  Ic  and  IIb  have  a  well  deck,  the 
area  of  which  must  be  at  least  30  per  cent,  of  the  total  deck  area. 
The  height  of  the  well  deck  above  the  water-line  at  all  points 
must  be  at  least  equal  to  one-half  per  cent,  of  the  length  of  the 
boat,  thb  height  rising  to  one  and  a  half  per  cent,  of  the  length  of 
the  boat  at  the  ends  of  the  well. 

The  freeboard  is  such  as  to  provide  a  reserve  buoyancy  of  at 
least  35  per  cent.     Reference  should  be  made  to  Fig.  127. 

Boats  of  Class  lie  have  &  flush  deck,  and  the  minimum  free- 
board is  independent  of  their  length  and  depend  only  on  their 
depth.  The  depth  of  the  boat  is  measured  vertically  from  the 
nndeFside  of  the  garboard  strake  to  the  top  of  the  deck  at 
Ttiie  aide  amidships,  and  the  freeboard  should  be  measured  from 
tho  top  of  the  deck  at  the  side  amidships  to  the  water-level 
rhen  the  boat  is  loaded.    (See  Fig.  128.) 


232  SfflPS'  BOATS 

The  freeboard  must  not   be  less  than  that  given   in  the 
following  table : — 

Depth  of  boat  Minimum  freeboard 

in  inches.  in  inches. 

12  2| 

18  3| 

24  5J 

30  6^ 

For  intermediate  lengths  the  freeboard  is  obtained  by  inter- 
polation. 

The  above  amounts  are  applicable  without  correction,  when 
the  boats  have  a  mean  sheer  equal  to  3  per  cent,  of  their  length. 
If  the  sheer  is  less  than  this  standard,  the  minimum  freeboard  is 
obtained  by  adding  to  the  figures  in  the  table  one-seventh  t)f  the 
difference  between  the  standard  mean  sheer  and  the  actual  mean 
sheer  measured  at  the  stem  and  sternpost;  no  deduction  is  made 
on  account  of  the  sheer  being  greater  than  the  standard  mean 
sheer,  or  on  account  of  the  camber  of  the  deck. 

It  is  important  to  notice  that  the  freeboard  values  given 
in  the  table  are  based  on  the  boat  floating  in.  fresh  water ^  the 
necessary  correction  must  be  made  if  the  boat  is  afloat  in  sea 
water. 

The  boats  are  loaded  with  weights  representing  the  equipment 
and  total  number  of  persons  obtained  from  the  capacity  nile, 
taking  165  lbs.  as  representing  one  person. 

If  the  boats  are  submerged  to  a  greater  depth  than  that  which 
provides  sufficient  freeboard  in  accordance  with  the  table,  then 
the  weights  are  adjusted  until  the  correct  freeboard  is  obtained, 
and  the  number  of  persons  assigned  to  the  boat  is  altered  accord- 
ingly. 

Draining  Arrangements. — Both  flush-deck  and  well-deck  pon- 
toon boats  are  fitted  with  efficient  means  for  quickly  freeing  the 
deck  of  water.  A  special  type  of  flap  non-return  valve  is  fitted 
between  the  deck  and  planking,  having  rubber  seatings,  which 
allows  the  water  on  the  deck  or  in  the  well  to  quickly  escape,  and 
at  the  same  time  prevents  the  water  below  from  coming  up 
through  the  orifices. 

The  number  and  size  of  the  orifices  are  determined  for  each 
class  of  boat  by  a  special  test. 

The  arrangements  are  such  that  in  the  case  of  a  lifeboat  of 
28  ft.  in  lengtli,  after  it  has  been  loaded  with  weights  equal  to 
its  total  complement  of  persons  and  full  equipment,  two  tons  of 


CONSTRUCTION  OF  PONTOON  LIFEBOATS      233 

water,  which  haa  been  placed  on  board,  must  be  cleared  from  the 
boat  in  (I  time  not  exceeding  the  following  : — 

Classea  lo  and  118  =  60  seconds 
Class  IIo  =20      „ 

For  boats  having  a  length  greater  or  loss  than  38  ft.,  the  weight 
of  the  water  to  be  cleared  in  the  time  stated  ia  to  be  directly 
proportional  to  the  length  of  the  boat. 

When  testing  the  boat  for  freeboard,  it  ia  usual  to  ascertain 
the  difference  in  draught  when  two  tons  of  weights  are  placed 
on  board.  Tliis  information  is  noted,  and  when  flooding  the  deck 
for  the  time  teat,  the  correct  draught  will  give  the  amount  of 
water  on  the  deck.  The  oriflces  are  covered  with  wood  and 
weighted  during  the  operation  of  flooding,  aud  at  a  signal  they 
are  aimnltaneously  lifted  for  the  commencement  of  the  time  test. 

An  arrangement  of  sleeve  -ports  is  sometimes  fitted  to  the 
flush-deck  boats  in  addition  to  the  scuppers  with  non-return 
valves,  but  with  the  "  all-wood  "  type  of  bulwarks,  some  better 
arraogemeat  is  considered  necessary. 

A  few  decked  boats  have  been  constructed  possessing  freeing 
potts  in  the  canvas  topsides,  provided  with  a  canvas  flap,  but 
they  are  considered  very  objectionable,  and  should  be  closed 
watertight  at  the  first  opportunity  by  fitting  canvas  covering 
pieces,  double  sewn,  and  the  approved  arrangements  fitted. 
A  successful  wooden  hinged  shutter  haa  yet  to  be  designed.  Few 
opportunities  have  been  given  recently  to  subiait  for  approval 
a  satisfactory  side  fieeing  port,  but  no  doubt  this  will  be  rectified 
in  the  future. 

It  is  generally  considered  that  in  those  types  of  boats  which 
depend  on  the  watertightness  of  the  deck  for  reserve  of  buoyancy, 
that  each  boat  when  stowed  in  a  tier  should  be  separately 
supported.  The  weight  of  one  boat  on  another  is  detrimental 
to  the  e£Eciency  of  the  deck  of  the  boat  underneath. 

Periodical  survey  of  pontoon  boats  already  forming  a  part  of 
the  equipment  of  pasiteni;er  vessels  must  be  undertaken  to  ascertain 
their  condition,  and  whether  they  are  fit  for  the  purpose  for  which 
they  were  orisinally  intended. 

Selections  are  mode,  and  the  boats  placed  in  the  water  without 
any  preparation  by  paiating  or  puttying. 

In  each  class  of  boat  under  review  bilge  pumps  were  at  one 
time  fitted  at  the  ends,  as  the  transverse  compartments  were  not 
then  made  individually  wat«rtight.  Before  the  bfiat  is  placed 
iu  the  wator  the  bottom  is  sounded  to  ascertain  if  there  is  any 


234 


SHIPS'   BOATS 


water  inside,  and  if  so  it  is  removed  as  far  as  practicable!     Hi 
small  amoimt  of  water  enters  the  deck  or  planking,  means  sxeM 
taken  to  prevent  the  difficulty  by  a  thorough  repair. 

At  least  one  boat  is  loaded  with  weights  conespouding  to  the 
full  complement  of  persons  and  equipment.  If  water  enters 
the  boat  after  three  hours,  in  such  quantity  as  to  become 
dangerous  to  the  stability  of  the  boat,  efficient  air-casea  are  fitted 
and  provided  in  as  large  unltfi  as  practicable,  allowing  three 
cubic  feet  of  air-case  for  each  person  assigned  to  the  boat. 

The  freeboard  of  the  loaded  boat,  after  the  air-cases  have  been 
fitted,  must  not  be  less  than  that  allowed  by  the  rules  in  force 
when  the  boat  was  built,  with  the  addition  thereto  of  any 
correction  that  may  have  been  made  for  camber  or  round  of 
beam  under  these  rules.  J 

If  the  unloaded  boats  which  have  been  placed  in  the  wat^l 
show  signs  of  leakage,  after  floating  for  three  hours,  they  must  be 
treated  in  the  manner  described.     In  addition  to  the  insertion 
of  the  air-cases,  the  hull  must  be  made  perfectly  watertight. 

The  efficiency  of  the  canvas  topsides  must  be  particularly 
noted  during  the  survey  as  to  whether  they  are  watertight  and  of 
sufficient  strength. 

The  very  best  materials  are  employed  during  the  constructioBj 
of  these  boats,  and  the  workmanship  must  of  necessity  be  t" 
highest  class. 

Before  construction  is  commenced  detailed  specifications  a 
drawings  miistJ)e  submitted  to  the  Board  of  Trade  for  approvi 
and  after  one  set  of  boats  is  completed,  severe  tests  must  1 
undertaken  and  prove  satisfactory  before  the  construction  i 
further  boats  of  the  particular  design  can  be  proceeded  with. 

These  tests  are  very  similar  to  those  already  fully  explained 
in  Part  IV.,  Section  E,  when  dealing  with  the  open  lifeboats  of 
Class  IIa,  except  that  a  further  test  is  required  to  ascertain  the 
efficiency  of  the  scupper  valves.     They  are  as  follows  ; — 

(a)  Strength ;  {b)  Freeboard ;  (c)  Flotation  (at  least  3  hours 
to  test  watertightness  of  hull) ;  (rf)  Deck-flooding  ;  (e)  Stabihty  ; 
(/)  Seating  and  rowing. 


SECTION  A.— MOTOR  BOATS 

The  motor  launch  for  use  on  board  a  veBBel  waa  for  many  yeais 
considered  a  luxurj'  equipment,  and  confined  to  one  or  two 
leading  shipping  companies,  but  recent  experience  has  proved 
the  necessity  of  an  extended  supply  not  only  for  the  purely 
passenger  type  of  vessel,  but  also  for  the  cargo-carrier. 

The  influence  of  the  war,  and  the  experience  of  many  of  our 
merchant  seamen  wlieii  caat  adrift  many  miles  from  land,  have 
naturally  increased  the  demand  for  all  foreign-going  vessels, 
both  cargo  and  passenger,  to  be  equipped  with  at  leaet  one 
motor  lifeboat. 

The  Anchor-Brocklebank  Steamship  Co.  have  taken  a  very 
commendable  action  iu  providing  atconmiodation,  on  most 
up-to-date  lincia,  for  a  large  number  of  cadets  on  several  of  their 
cargo  vesseb.  These  cadets  are  educated  and  take  a  sliare  in 
the  actual  routine  of  the  daily  work  and  experience  on  board ; 
they  thus  receive  a  training  of  the  most  practical  and  thorough 
character.  Includeil  in  the  equipment  ia  a  motor  boat  for  the 
use  of  the  cadets  as  a  means  of  increasing  their  knowledge  ui 
seamanship.  Messrs.  Alfred  Holt  and  Co.  and  other  companies 
carry  power  boats  on  several  of  their  cargo  vessels. 

A  large  number  of  our  Mercantile  Marine  officers  have  been 
attached  to  the  Fleet  Auxiliary  vessels,  on  which  motor  boats  are 
usually  carried,  and  the  very  many  advantages  which  have  been 
experienced,  and  the  speed  with  which  the  passage  can  be  made 
from  the  vessel  at  the  anchorage  to  the  shore,  have  greatly 
increased  the  desire  to  have  a  power  boat  on  board,  as  a  part  of 
the  equipment. 

Several  countries  now  insist  on  the  provision  of  at  least  one 
motor  boat  on  foreign-going  vessels. 

The  boat  equipment  of  many  of  our  large  passenger  liners 
includea  one  or  two  motor  lifeboats  or  motor  lowing  biats.  The 
frontispiece  indicates  in  the  foreground  a  motor  boat  supplied  to 


J 


236  SHIPS'  BOATS 

the  R.M.S.  Aquitania  by  Messrs.  Sir  John  Thomycroft  and  ( 

Ltd.     Even  a  cui'aory  ylance  at  the  photograph  will  give  o 


idea  of  the  quality  of  constructiou,  and  Figs.  13i-136  show  thn 
geaeral  arraQgeiueiit  of  wiroloas  equipment. 

One  very  great  advantage  with  this  type  of   motor  1 
is,  that  in  case  of  disaster,  it  caa  be  utilised  ^  a  "  mothoc] 


MOTOR  BOATS  237 

ship  "  for  towiuf;  the  ordinary  pulling  lifeboate  and  keeping 
them  in  touch  with  one  another,  and  for  the  purpose  of  supply- 
ing them  with  medical  comforts,  blankets,  etc.,  if  required. 

The  installation  of  wirelees  telegraphy  is  an  obvious  advantage, 
and  in  tlie  light  of  present-day  experience,  and  the  general  advance 
in  practical  and  scientiSc  equipment,  the  dangers  of  an  open  sea 
passage  are  considerably  reduced.  The  apparatus  ha£  a  range  of 
abnat  50  miles  for  transmitting  and  consequently  would  be  able 
to  keep  in  constant  coram imication  with  steamers  in  the  vicinity. 

The  .hull  is  built  of  teak  or  mahogany  and  fitted  with  a 
Thomycroft  4-cylinder  motor  of  30  B.H.P,  starting  on  petrol  and 
running  on  paraffin. 

Theapeed  under  power  only  is  about  7  knots,  and  the  carrying 
weight  of  the  boat  in  running  condition,  without  passengers  on 

^l)o»^,  about  5^  tons. 
The  dimensions  are :  Length  30  ft. ;  breadth  9  ft.  6  ins. ; 
4epth  4  ft.  6  ins. 
Generally  speaking  the  design  is  probably  one  of  the  best  and 
most  practical  proposals  to  meet  the  difficulties  experienced  in 
life-saving  at  sea.  and  although  it  is  not  designed  to  comply 
with  the  Board  of  Trade  requirements  for  a  ship's  lifeboat,  the 
^   equipment  ia  very  efficient  and  complete, 

I        Another  design  is  shown  in  Figs,  137  and  138,  which  was 

■  constructed   to   meet   alt    the   Board   of   Trade   requirementa. 

Buoyancy  air-casea  are  fitted  in  sufficient  quantity  to  provide 

the  reserve  of  buoyancy  for  the  full  number  of  persons  carried 

and  the  weight  of  the  motor  and  gear.     The  functions  of  this 

boat  in  addition  to  the  larger  space  for  the  accommodation  of 

I  persons,  are  practically  the  same  as  the  boat  previously  referred 

1.     It  is  fitted  with  a  X5  B.H.P.  motor,  giving  a  speed  of  6  knots. 

Two  motor  lifeboats  as  described  were  carried  on  the  R.M.S. 

1  Brilannic,  which  was  lost  during  the  war  in  the  Medit«rranean 

[  Sea. 

The  demand  for  power  Ufeboata  during  the  past  four  years 
I  has  beem  so  great  that  to  increase  the  usefulness  and  widen  the 
1  radius  of  action  of  the  ordinary  pulling  lifeboats,  portable  outboard 
I  motori  have  been  fitted. 

The  United  States  authorities  stipulate  an  outboard  motor 
I  to  be  carried  and  attached  to  a  lifeboat  for  towing  purposes  in 
lease  of  necessity. 

The  writer  has  had  some  experience  with  the  "  Evinrude," 
Itiie  "  Waterman  Porto,"  and  the  "  Simplex"  outboard  motors, 
Itlie  last-named  being  supplied  by  Messrs.  W.  Macroillan  and  Co. 


J 


SHIPS'  BOATS 


MOTOR  BOATS 


239 

1  Fig.  1^9  represents 


[  of  Alloa,  Scotland.     Tlie  photograph  shown  ii 
1  the  3J-^  H.-P.  model,  which 

is  of  sturdy  construction  and 

designed  to  meet  the  reason- 
able  necessities   of   a  ship's 

boat.      One   of    the   special 

features  of  this  motor  is  the 

large   nidder   by   which   the 

boat  may  be  easily  steered, 

whether  the  motor  is  runnini!, 

■  not.      Reversing  gear   is 

so  att«d. 

The  two  first-named  oiit- 

I   board    motors   are   too    well 

,  known  to  require  any  special 

I  description.     A  large  number 

[  of  these  are  now  in  constant 

I  operation  in  all  parta  of  the 

I  world.      Fig.    140   illustrates 

I  die  Waterman  Porto  motor, 

'  which  can  be  easily  attached 

to  the  transom  and  sternpoat 

of   an  ordinary  ship's  boat, 

the  anangement  of  clamps  is 

very  simple,  and  so  designed 

as  to  allow  the  weight  of  the 

engine  to  come  on  the  boat's 

stem  and  cause  no  twisting 

action. 

The  motor  is  of  the  3-port, 

2-oycle  type,  which,  owing  to 

its  simplicity,   is  considered 

most  satisfactory.  The  crank- 
case  and  tiller  are  oast  from 

a  special  copper  alloy  which 

iaspeciallyadapted  for  marine 

or  salt  water  use. 

The  gears  are  designed  to 

give  one  turn  of  the  propeller 

wheel  for  every  one  and  one- 
half  turns  of  the  engine. 

The  fuel  tank  is  of  large  capacity,  and  carries  sufficient  fuel 

for  several  hours'  use. 


I 


they  appear  to  have  given  great  satisfaction  for  the  piirposs  J 
intended.  I 

It  is  generatly  admitted  that  in  a  motor  lifeboat  the  engine  j 
should  be  of  such  power  aa  will  be  sufficient  to  allow  the  launch  1 
to  tow  other  boata.     The  whole  of  the  mechanism  and  wiling 
must  be  enclosed  and  protected  from  the  weather,  the  greatest 
enemy  to  the  internal  combustion  engine  being  dampness  or  spray. 

During  tlie  period  the  motor  boat  ia  stowed  in  the  chocks  j 


for  every  event,  and  (ipportunity  taken  when  in  pott  to  give  the 
boat  a  spin.  Periodical  attention  must  be  given  and  ahould  form 
part  of  the  ordinary  boat  drill. 

One  of  the  miatakea  that  would  probahly  be  made  in  an 
ordinary  cargo  boat,  if  legislation  made  it  necoaaary  for  every 
vessel  to  be  supplied  with  a  power  boat,  wonkl  bo  that  of  nej^lect. 
It  requires  the  closest  supervision,  even  under  present  circuin- 
stancee,  to  see  that  the  ordinary  iifeboate  are  kept  in  a  iit  a 


SHIPS'  BOATS 

proper  condition,  and  with  the  addition  of  mechaniccd  propiil^n 

to  the  statutory  equipment,  the  daily  routine  of  attention  to 
details  would  be  increased.  It  is  quite  safe  t«  state  that  unless 
adequate  care  and'  oversight  are  given  to  the  condition  of  the 
motor  and  its  accessories,  the  vessel  is  better  served  without  a 
niot«r  boat. 

The  Rules  for  Life  Saving  Appliances  state— 
"  (1)  An  approved  motor  boat  may  be  carried  as  a  lifeboat 
Bubjoct  to  the  following  conditions  : — 

"  (a)  It  shall  comply  with  the  requirements  for  a  lifeboat  of 
Class  I.,  and   proper   appliances   shall   be  provided 
for  putting  it  into  the  water  speedily. 
"  (6)  It  should  be  adequately  provided  with  fuel,  and  kept  so 

as  to  be  at  all  times  fit  and  ready  for  use. 
"  (2)  When  the  number  of  lifeboats  is  less  tjjan  ten,  one  of 
'■  them  may  be  a  motor  boat.  Wliere  the  number  of  lifeboats  is 
'•  not  less  than  ten,  two  of  them  may  be  motor  boata.  The  Board 
"  of  Trade  may,  on  the  application  of  the  owner,  allow  a  greater 
"  number  of  motor  boats  to  be  carried,  if  they  are  satisfied  that 
"  the  efficiency  of  the  life-saving  equipment  will  not  thereby  be 
"diminished. 

"  (3)  In  fixing  the  volume  of  the  internal  buoyancy  and 
"  where  fitted,  the  external  bouyancy,  regard  should  be  had  to 
•'  the  difference  between  the  weight  of  the  motor  and  its  acces- 
"  sories  and  the  weight  of  the  additional  persons  which  the 
"  boat  could  accommodate  if  the  motor  and  its  accessories  were 
"  removed," 

The  recomtnendadoius  of  the  Departmental  Committee  on  Bonis 
and  Davits,  when  dealing  with  the  question  of  mechanically 
propelled  boats,  were  as  follows  : — 

"  We  recommend  that  the  carriage  of  mechanically  propelled 
boats  should  be  optional  for  all  classes  of  steamships.  But  since 
the  efliciency  of  a  lifeboat  for  saving  life  is  not  diminished  because 
it  is  fitted  with  a  motor,  we  recommend  that  whatever  be  the 
number  of  boats  carried  on  any  ship,  the  shipowner  should  be 
allowed  tlie  option  of  carrj-ing  one  mechanically  projielled  boat 
if  he  so  desires. 

"  In  the  case  of  a  vessel  carrying  a  considerable  number  of 
lifeboats  it  would  be  preferable  to  carry  a  small  number  of 
high-powered  motor  boats  rather  than  a  large  number  of  low- 
powered  boata.  Instead  o£  increasmg  the  number  of  motor  boats 
on  a  scale  corresponding  with  the  total  number  of  boats  caiTied, 
the  size  and  power  of  the  motor  boats  should  be  increased  as  the 


^H      Durubet 
^f      on  each 


MOTOR   BOATS  243 

In  f^eneral,  two  motor  boate 


Dumber  of  other  boats 

on  each  side  should  be  sufficient. 

The  reasons  which  lead  us  thus  to  limit  the  number  of  motor 
boats  carried  are  mainly  connected  with  considerations  of  tlie 
efficient  supervision  and  maintenance  of  a  Iarf;e  number  of  engines 
and  with  the  difficulty  of  ensiuing  that  one  or  more  men  who  are 
conversant  with  the  working  of  it  motor  would  be  assigned  to  each 
motor  boat  in  the  confusion  of  taking  to  the  boats  in  an  emergency. 
Further,  in  view  of  the  fact  that  an  increasing  number  of  ships 
are  being  fitted  with  wireless  telegraphy,  it  is  not  desirable  that 
the  ships'  boats  should  proceed  far  from  the  neighbourhood  of  the 
disaster.  The  motor  boats  would  be  used  for  keeping  the  other 
boata  together  and  generally  shepherding  them,  rather  than  for 
towing  a  number  of  boats  a  long  distance.  In  certain  trades, 
of  course,  they  could  go  reaaonable  distances  in  search  of  succour. 
Also  one  or  two  powerful  motor  boat*)  might  bo  of  service  in 
rendering  assistance  in  bad  weather  on  a  lee  shore.  In  these 
circumstances  we  recommend  that  the  motor  boats  carried  should 
be  as  large  and  as  powerful  as  possible,  having  regard  to  the 
size  of  the  ship  and  the  means  available  for  handling  and  launching 
such  boats. 

"  As  to  the  type  of  engine  which  is  moat  suitable  for  this 
purpose  it  may  be  said  that  ^team  is  of  little  value  owing  to  the 
delay  involved  in  starting  the  engine.  The  use  of  petrol  in  bulk 
is  viewed  with  disfavour  owing  to  the  risk  of  fire  and  explosion. 
On  tlie  whole,  therefore,  we  recommend  the  type  of  engine  known 
commercially  as  the  paraffin  engine.  This  engine  is  simple,  safe, 
and  rehable,  and  there  are  several  satisfactory  patterns  on  the 
market.  Even  with  this  engine,  if  iwrafliii  alone  is  used,  con- 
siderable delay  iji  starting  the  engine  may  result  from  the  difficulty 
of  heating  the  vaporiser  under  unfavourable  conditions  of 
weather.  The  use  of  a  small  quantity  of  petrol,  however, 
niatorially  facilitates  the  starting,  and  we  have  seen  a  syBtem 
of  petrol  starting  which  obviates  the  ordinary  dangers  arising 
from  the  use  of  petrol  in  bulk.  The  petrol  is  carried  in  email 
hermetically-sealed  cylinders  which  contain  one  starting  charge 
only,  so  that  the  possibility  of  leakage  and  evaporation  ts 
minimised. 

"  Special  attention  should  be  given  to  making  the  ignition 
gear  damp-proof,  and  the  casing  of  the  engine  watertight. 

"  Evidence  has  been  put  before  us  which  shows  that  fuel 
could  easily  be  carried  to  cover  a  radius  of  100  miles.  This 
quantity  of  fuel  should  be  the  minimimi, 


SHIPS'  BOATS 


244 

"  Iq  order  to  ensure  that  the  engines  are  always  in  working 
order,  they  should  be  started  up  at  every  boat  drill.  Steps  should 
be  taken  to  secure  that  this  rule  shall  always  be  observed.  In 
order  that  no  damage  may  result  from  starting  the  cngiDe  on  the 
veasel's  deck,  provision  should  be  made  for  proper  water  circula- 
tion in  such  cases,  when  the  design  of  the  engine  necessitates 
water-coo  Itn}^." 

Construction  ol  Hull— There  are  very  few  features  connected 
with  the  construction  of  the  frame  and  the  method  of  working 
the  planking,  which  have  not  already  been  explained  in  full 


■ 
I 


detail  in  the  section  dealing  with  the  construction  of  ordinal] 
pulling  boat**. 

The  planking  of  the  smaller  type  of  motor  launches  is  sum 
times  worked  on  the  "  cliuker  "  method ;  but  the  great  majoritn 
of  ships'  motor  boata  are  planked  on  tbe  "  car\-el "  or  "  doubf 
skin "  system,  A  Hush  surface  on  the  outside  ofiers  lee 
resistance,  and  gives  the  best  underwater  form  for  the  moa 
satisfactory  speed  results.-  The  larger  type  of  motor  boats  i 
eonstructwl  on  the  "  carvel "'  principle  in  many  caseSj  but  is 
variably  the  "  double-skin  "  planking  is  used,  as  in  this  casa  { 
naturally  follows  that  the  hull  is  much  stronger  and  better  able  ti 
withstand  the  climatic  changes  of  atmosphere.  Each  of  tha 
methods  has  already  been  fully  described  in  Section  A  of  1 


L 

1 

L 

p  ...„„    J 

^B IV.,  and  it  will  serve  ho  useful  purpose  to  refer  to  the  question          ^H 
^B  again  in  any  detail.                                                                                     ^H 
^m       Practice  varies  even  in  the  limited  area  of  the  Firth  of  Clyde,           ^M 
^B  where  in  one  yard  the  section  moulds  are  so  arranged  as  to  allow           ^| 
^B  the  motor  boat  to  be  constmcted  upside  down,  in  similar  fashion           ^B 
^V  tc>  thiit  which  in  atlopteil  whi-ri  Ihi'  fiinin'  is  c'lmplete  and  the            ^M 

H  Via.  142.— Mo 

V  planldng  ha 

collapsible  b 

The  boat 

planldng  ha? 

^        Figs.  141 

^■.construction 

^B  diagonal  sys 

■^  (ore-aad-aft- 

The  phot 

JdcGnier  an 

P^ 

on   by  Mo8s™. 

eboate  with 

on  until  the 

in  course  of 
rked  on  the 
■,  fitted  in  a 

■is  of  Messrs. 
ated  on  the 

'    l5^a^> 

tor   boat.     Fore   end   view.      Uiiddr   oouslructi 
MuGruer  and  Co..  Ltd.,  Clynder,  Siotland. 

3  commenced,  in  the   case  of   the  lil 

ulwarks. 

is  not  turned  over  into  its  upright  poait 
been  completely  finished  and  fastened, 
and  142  illustrate  a  20-ft.  motor  boat 
having  an  inner  skin  of  mahogany',  wi 

■em,  and  an  outer  skin  also  of  mahogan 

direction. 

ograph  was  taken  in  one  of  the  boat-she 

1  Co.,  Ltd.,  of  Clynder.  beautifidly  situ 

246  SHIPS'  BOATS 

shoreti  of  the  Garelocli,  Scotland,  &iid  witliin  easy  accms  to  boi 
of  the  best  timber  in  the  country. 

The  work  turned  out  by  this  firm  is  of  the  very  highest  class, 
and  the  name,  coupled  witli  that  of  Messrs.  Fyfe  of  Fairlie, 
well  known  throut^hout  Great  Britain  among  shipbuilders  and 
superintendents,  as  being  the  hall  mark  of  excellence.  The  writer 
hat*,  therefore,  taken  the  libeity  to  insert  in  this  section  a  complete 
specification  for  the  hull  of  the  standard  22-ft.  motor  boat^^ 
supplied  by  Meaara.  McGrucr  and  Co..  Ltd.,  and  which  conformft] 
to  all  the  requirements  of  the  Board  of  Trade. 

The  lines  of  a  motor  boat,  in  the  first  place,  have  to  be  veiy 
carefully  conaidered.  not  only  in  their  apphcation  to  certain 
features  of  importance  considered  in  the  Board  of  Trade  Instruc- 
tions, but  more  especially  to  the  question  of  speed  and  displace- 
ment in  their  relation  to  stability,  and  the  service  for  which  th«J 
boat  is  intended. 

It  therefore  follows  that  moul<i3  have  to  be  made  to  ths 
faired  lines  on  the  floor,  in  the  manner  described  in  Section  A  ol 
Part  IV. 

It  is  very  essential  that  the  combinations  which  form  the  frame 
or  backbone  of  the  boat  should  be  specially  considered  in  relation 
to  the  stresses  they  will  be  called  upon  to  resist. 

If  the  engine  is  installed  amidships,  then  it  becomes  necessary 
,   to  stiffen  the  boat  up  longitudinally  to  counteract  the  tendency 
to  sag,  by  fitting  a  substantial  keelson. 

In  the  smaller  type  of  motor  boat,  owing  to  the  desirability 
of  keeping  the  eufrine  as  low  down  as  practicable  for  the  purpose 
of  stability,  there  is  insufficient  space  between  the  fly-wheel  and 
hog-piece  to  allow  for  the  fitting  of  a  keelson  ;  the  longitudinal 
strength  in  this  case  is,  therefore,  maintained  by  fitting  two  bilge 
or  side  stringers  of  heavy  scantlings. 

Special  attention  is  given  to  the  combination  of  materiala 
and  fastenings  in  way  of  the  stempost  and  deadwood,  to  takej 
the  thrust  and  continual  vibration  set  up  by  the  propeller  and 
shaft. 

Again,  the  important  matter  of  how  the  lifeboat  is  to  be  lift( 
and  the  position  of  the  lifting-hooka  to  suit  the  particular  ty] 
of  davit  fitted  on  the  vessel,  must  receive  close  attention. 

If  at  all  practicable,  fixed  lijting-liooka  should  he  fitted,  but' 
the  design  of  the  boat  may  be  such  as  to  prevent  this  being  done, 
and  in  that  case  there  is  no  alternative  but  to  fit  chain  slings. 
Proposals  have  been  put  forward  to  supply  wire  slings,  but  there 
is  always  an  element  of  doubt  as  to  the  continued  efficiency  olj 


I 


MOTOR  BOATS 


247 


these,  having  legoid  to  the  effect  of  the  weather  and  the  possibility 
of  corroflioit. 

iniera  is  no  donbt  that  chain  alinga  support  the  boat  and 
diBtadbute  die  Btceeses  along  the  full  length  of  the  hull  in  a  mote 


Fifl,  U5.— Forward  oomU  nation*. 
Conatniotjon  of  end  combinatiooe  loi  s  22-tt.  motor  boat. 


satisfactory  way  than  do  fixed  hooks ;  but,  on  the  other  hand,  there 
ia  not  the  steady  control  with  the  slings  which  is  associated 
with  filed  hool<s,evca  with  steadying  chains  fitted  to  the  former. 
The  tendency  is  for  the  boat  to  move  from  the  upright  position  by 


248 


SHIPS'  BOATS 


the  shifting  of  the  occupants  of  the  boat  or  by  the  movement  of  the 
equipment.    The  point  is  worthy  of  consideration,  particularly 


f/lUAfG  ^*CC£ 


Fig.  146. — Midship  section  of  a  22*ft.  motor  lifeboat. 


r\ 


I 


CAP^//fO 


'^    '       ¥  :  'tJ        V    I 


when  one  has  to  provide  for  the  difficult  circumstance  when  the 
boat  may  be  filled  with  panic-stricken  passengers. 

The  drawings  shown  by  Figs.  14^145, 
give  the  disposition  of  fastenings  for  a 
22-ft.  motor  boat,  having  fixed  hooks  to 
suit  "  Welin  "  davits,  which  lift  the  boat 
at  a  distance  of  about  17  in.  from  the 
extreme  ends. 

The  sternpost,  stem,  deadwoods,  and 
transom  knee,  should  be  secured  from 
material  grown  to  shape  and  of  the  very 
best  quality. 

It  is  somewhat  difficult  at  times  to 
secure  the  after  deadwood  in  one  piece, 
and  the  difficulty  is  obviated  by  carefully 
checking  the  details  together  and  strapping 
with  side  pieces. 

Sufficient  material  must  be  left  in  the 
deadwood  to  give  support  to  the  pro- 
peller shaft  and  to  house  the  stuffing  gland. 
Double  securing  bolts  should  be  fitted  to 
the  keel  and  deadwood,  and  arranged  to 
clear  the  shaft  without  weakening  the 
combination.  Provision  should  be  made 
for  withdrawing,'  the  shaft  by  fitting  a  hinged  metal  support 
between  the  heel  of  sternpost  and  transom,  as  shown  in  Fig.  143. 


I 


Pvaarfi 


H^ 


Fio  147. — Details  of  gun 
wale  for  motor  lifeboat. 


MOTOR  BOATS 


t 


i 
I 

The  midship  section  of  the  22-ft.  motor  boat  is  shown  in 
Rg.   146.     Care  must  be  taken  before    the   construction  is 


SHIPS'  BOATS 

commenced  to  ascertain  the  space  that  will  be  taken  up  by  the 
bucyancy  air-cases,  having  in  view  the  additional  buoyancy 
which  is  required  to  support  the  weight  of  the  motor  and 
its  accessories.  It  is  a  very  difficult  problem  to  house  these 
air-casea  without  encroaching  on  the  available  space  for  seating, 
working  around  the  engine,  and  locker  accommodation.  Air- 
caae'i  must  not  be  fitted  on  the  floor  of  the  boat,  and  athwartehip 
air-cases  are  considered  objettionable,  but  are  difficult  to  avoid. 

The  method  of  arriving  at  the  correct  cubic  capacity  of  the 
buoyancv  air-cases  to  be  fitted,  ia  dealt  with  in  detail  under 
ScctionCof  Part  VI. 

Fig.  147  shows  the  detail  of  gunwale  and  nash-strake  c<wi?»ino- 
lion.  The  toimdini;  of  the  capping-edge,  and  the  fitting  of  a 
fillet  piece  between  capping  and  wash-atrake,  give  a  pleasing 
finish  to  the  boat. 

Fig,  148  shows  in  outline  the  general  arrangement,  and  the 
following  specification  indicates  the  scantlings  of  the  various 
component  parts,  of  the  22-tt.  motor  lifeboat  already  referred  to. 
There  is  seating  accommodation  for  17  persons  in  this  particular 
boat. 


SPECIFICATION    FOR   A   ST.VNDARD    22-ft.    MOTOR 
LIFEBOAT, 

C'ON.STRUCTED   BV   MESSRS,    McGrL'ER  AND  Co.,   LtD..   Ci.YNDER, 

Dumbartonshire. 

I}ifnenaions. 

Length  {between  outside  of  plank  rabbets)        .     .  22  ft.    0  in. 

Length  overall  (about) 22  ft.    4  in. 

Breadth 7  ft.    0  in. 

Depth  to  top  of  gimwale  capping 2  It.  10  in. 

General. — The  boat  to  be  built  under  cover  and  protected  from 
weather  during  constniction.  Except  where  otherwise  stated 
all  fastenings  to  be  of  copper  and  to  Board  of  Trade  requirementa. 
All  materials  used  to  be  of  the  best  quality.  The  timber  to  be 
clean  grown,  well  seasoned,  grown  to  fonu  where  required,  and 
free  from  defects.  All  iron  and  steel  work  to  be  galvanised. 
To  be  of  superior  workmanship,  and  all  materials  to  be  of  the 
best  quality.  The  life-lines  round  boat  to  be  of  good  yacht 
quality  white  manila.  OJiinwaies  to  be  well  finished  in  every 
respect,  the  sheer  of  the  boat  to  be  neat  and  "  eye-sweet,"  and 


MOTOR  BOATS  251 

in  accordance  with  the  standard  requirements  of  4  per  cent,  of  the 
kngth. 

The  motor  boat  during  construction  will  be  under  the  survey 
of  a  ahip  surveyor  of  the  Board  of  Trade. 

1.  Ked. — Canadian  rock  elm  in  one  length,  sided  3  in., 
moulded  4  in. 

2.  Hog. — Canadian  rock  elm  in  one  length,  sided  5  in.,  and 
moulded  1  in.,  clench  fastened  through  keel  with  suitable  copper 
naik  and  washers. 

3.  Slem. — ^British  oak,  well  grown  to  form,  sided  3  in.,  and 
moulded  4  in.,  scarphed  to  keel,  and  fastened  with  copper  clench 
bolts  and  nails  as  required. 

4.  Apron. — Euglirfi  elm,  moulded  3|  in.,  and  sided  to  fay 
its  whole  thickness  against  the  planks  of  boat,  fastened  with 
suitable  clench  nails  and  bolts. 

6.  Fore  Deadtoood, — British  oak  grown  to  form,  moulded  and 
sided  to  fay  against  the  plank  throughout.  Fastened  with 
suitable  copper  clench  nails  or  bolts. 

6.  StemjK)st. — British  oak,  grown  to  form,  sided  5  in.,  and 
moulded  to  suit  the  form  of  boat,  fastened  with  suitable  copper 
clench  nails  and  bolts. 

7.  After  Deadiwod, — English  elm,  sided  5  in.,  moulded  as 
required,  and  suitably  fastened  with  copper  bolts. 

8.  Transom  Knee. — ^British  oak,  grown  to  form,  sided  3  in., 
and  moulded  as  shown  on  the  plan,  fastened  with  copper  nails 
and  bolts. 

9.  Transom, — English  elm,  1 J  in.  thick  with  bent  cant  timber 
against  the  inside  surface.  Clench  fastened  to  transom  knee  with 
copper  nails. 

10.  Planking, — Carvel  built  of  Honduras  mahogany  f  in. 
finished.  Fourteen  strakes  each  side.  Six  scarphs  each  side  to 
be  allowed.  Fastened  through  lands  with  clench  nails  No.  12 
gauge,  and  through  timbers  with  No.  10  gauge. 

11.  Timbers, — Steamed,  of  Canadian  rock  elm,  spaced  5J  in. 
centre  to  centre,  sided  IJ  in.,  moulded  |  in.  To  be  in  one  length, 
except  at  the  ends  where  they  will  be  mortised  into  the  deadwoods. 

12.  Gummles, — Canadian  rock  elm,  in  one  length,  2  in.  deep 
and  1|  in.  wide,  the  space  between  the  timbers  to  be  filled  in 
with  pine,  and  fastened  through  each  timber  with  copper  clench 
nails. 

13.  Quarter  Knees  and  Breasthook. — British  oak,  grown  to 
form,  to  be  fitted  to  cross-piece  and  gunwales,  and  fastened  with 
copper  clench  nails  and  bolts. 


SS3  SHIPS'  BOATS  V^^^^H 

14.  Rinngi. — Canadian  rock  elm,  in  one  length,  etuAi  side 
tounded  on  inside  eddies,  and  fastened  through  each  timber  with 
copper  clench  nails. 

15.  Ruijters. — Canadian  rock  elm,  in  one  length,  each  side, 
IJ"  X  li',  fastened  through  each  timber  with  copper  clench  naiU. 

16.  Bilge  Stringers. — Canadian  rock  eUn,  3"  x  IJ',  fitted  full 
length  ot  boat  in  one  piece,  and  secured  to  every  alt«mat«  timber 
with  copper  clench  nails,  gauge  10. 

17.  Capping  to  Gunwales. — Canadian  rock  elm  in  one  length, 
f  in.  thick,  and  broad  enough  to  cover  gunwales,  timbers,  sheer 
fltrake,  and  to  project  |  in.  over  sheer  strake-,  where  it  will  be 
rounded  to  form  bead  moulding.  To  be  fastened  with  copper 
sjiike  nails, 

18.  Deck  Bea»/w.— British  oak,  sided  1  in.  and  moulded  1 J  in. 
at  centre,  and  tapered  towards  ends.  Round  of  beam  to  be 
3  in.  in  6  ft.  A  ledge  to  be  fitted  under  beams  at  boat's  aide, 
through-fastened  at  each  timber,  the  beam  ends  to  be  clench- 
fastened  to  this  ledge. 

19.  Deck  Plank. — Teak  or  mahogany,  |  in.  thick  and  3  in. 
wide.  To  be  fastened  to  beam  with  brass  screws  and  doweUed. 
Seams  to  be  caulked  and  paid  with  marine  glue. 

20.  Coaming  to  be  worked  as  shown  on  plan,  Canadian  rock 
elm,  I  in.  thick,  fastened  with  brass  screws  and  doweUed.  To  be 
further  secured  with  six  gun-metal  knees  secured  to  outside 
coaming  and  capping.  Depth  of  coaming  to  be  6  in.  above 
gunwale  capping, 

21.  Jtfotor  Bearers. — Selected  pitch  pine  or  fir,  sided  2J  in., 
moulded  to  suit  engine  and  form  of  boat.  Not  less  than  9  ft.  long. 
Fastened  with  through  copper  bolte  about  12  in,  apart.  To  be 
further  strengthened  transversely  by  an  oak  floor  at  each  end  of 
the  engine,  the  floors  to  be  clench-fastened  through  keel  and 
plank,  a  clench  bolt  to  go  through  bearer,  floor,  and  plank.  The 
space  under  the  engine  to  be  filled  in  with  pine  to  the  height  of  the 
timbers  and  lined  with  fourteen-ounce  copper  to  form  an  oiltight 
saveall.     Motor  to  be  installed  in  accordance  with  best  practice. 

22.  WaUrtight  Bulkhends. — ^Teak  or  mahogany,  two  skins, 
each  I  in.  thick,  with  oiled  calico  between.  Rtt«d  at  each  end 
of  the  motor  space,  and  made  watertight  up  to  the  height  of  the 
thwarts.     Each  bulkhead  to  have  suitable  drain  valves. 

23.  Thwarts  and  Benches. — Teak  or  mahogany,  1  in.  and  |  in. 
in  thickness  respectively.  To  be  supported  with  ebn  or  oak 
knees  where  necessary,  and  fastened  with  brass  screws. 

24.  Stem-sheets  and  6Vfl/i*JM/8.— Laid  on  fir  bearers  2'Xl'. 


^1^. 


MOTOR   BOATS 


253 


Teak  or  lutiliogany  side  pieces  J  iii.  thick,  fastened  down  with 
brass  screws.  Teak  or  mahogany  skirting  worked  above  side 
pieces  and  screwed  to  timbers.  Two  poiiable  elm  or  teak  J  in. 
mesh  gratings  fitted  between  side  benches. 

25.  Bottom  Boards  tn  Fore  Cockpit. — Red  pine  or  fir  J  in.  thick. 
Mode  portable  where  necessary. 

26.  Rudder  mid  Tiller. — The  rudder  to  be  EngJiah  ehn  in 
one  piece,  1 }  in.  thick,  bearded  to  I  in.  at  the  after  edge.  The 
head  to  be  oval,  formed  by  |  in.  cheeks.  A  gun-metal  cap  to  be 
secured  on  top  through  which  the  forged-iron  tiller  with  turned 
wood  handle  will  be  fitted,  and  made  secure  with  ornamental 
nuts.    .Rudder  hangings  to  be  gun-metal. 

27.  LiJUng  Hooks  and  Keel  PifUes.—^o  be  of  the  fixed  type 
and  in  accordance  with  Board  of  Trade  requirements. 

28.  iSfemtand.— Galvanised  wrought  iron.  Skeg  to  be  gun- 
metal. 

29.  Staves. — Ensign  and  pendant  staves  to  be  of  ash,  IJ  in. 
meter. 

.  Canvas  Gear. — Boat  cover  and  canopies  to  be  a  good  fit. 
11.  Motor  Casing. — ^To  be  teak,  with  sliding  panels  and  hinged 
I  lids. 

32.  Towing  Bollards. — Oak  towing  bollards  to  be  fitted  on 
each  side  of  stem,  and  one  each  side  of  bow,  with  metal  pins ' 
through  the  centre  of  each  bollard. 

33.  Buoyancy  Air-Vases. — Copper  buoyancy  tanks  of  sufficient 
capacity  made  to  fit  the  boat's  sides  and  cased  with  teak  or 
mahogany. 

3i,  Storm  Hoods. — Two  storm  hoods,  each  fitted  on  three 
I  in.  galvanised  iron  rods,  hinged  at  coaming,  and  laced  to  brass 
hooks  and  eyes  on  coaming. 

35.  Deck  FiUitujs. — Two  galvaui.sed  iion  mooring  bollards. 
Four  galvanised  iron  fairleada. 

36.  Paintiwj. — Three  coats  of  best  paint  or  varuisli,  inside  and 
outside  to  approval.  The  planking  of  boat  to  be  sandpapered, 
fmd  paintwork  to  be  first  class.  Decks  and  internal  fittings  two 
coats  of  varnish. 

37.  Weig}(t. — Approximate  weight  complete=2'2  tons. 

38.  Seating  Copaci/y.— Proper  seating  accommodation  is  to 
be  provided  for  17  persons. 

39.  Notes. — Cast  brass  plates  with  ship's  name  in  one-inch 
letters  to  be  screwed  to  etern,  anil  similar  brass  plate  with 
Port  of  Registry  fitted  at  bow.  Portable  rope  fender  fitted 
afcbow, 


254  SHIPS'  BOATS 

40.  Outfit, — In  accordance  with  the  requirements  of  the  life- 

Saving  Apphances  Rules,  viz. : 
Six  oars  for  rowing. 

One  oar  for  steering,  blade  painted  green. 
Two  plugs  with  chains. 
Eight  crutches,  including  one  for  steering  oar,  attached  to 

boat  by  chains. 
Sea  anchor,  canvas,  with  20  fathoms  of  tripping  line  and  rope 

trailer  attached. 
Bailer. 

Two-gallon  galvanised  iron  bucket. 
Painter,  20  fathoms  in  length. 
Boathook. 
Water  breaker  or  galvanised  iron  tank,  holding  one  quart  for 

each  person  that  the  boat  is  deemed  fit  to  carry. 
Suitable  metal  dipper,  tinned,  attached  to  breaker  by  lanyard. 
Two  hatchets,  one  at  each  end  of  boat. 
The  rudder,  tiller,  bailer,  bucket,  and  hatchets  to  be  secured 

to  the  boat  by  sufficiently  long  lanyards. 
Copper  or  metal  lantern,  trimmed  with  oil  and  sufficient 

to  bum  for  eight  hours. 
Liquid  compass  in  binnacle,  to  latest  requirements. 
Air-tight  case  to  hold  34  lbs.  of  biscuits,  and  spanner  attached 

for  opening  plug. 
One  gallon  of  vegetable  oil. 
Oil  distributor,  to  be  attached  to  sea  anchor. 
One  dozen  self-igniting  red  lights  in  watertight  tin. 
Box  of  suitable  matches  in  watertight  tin. 
The  following  are  provided,  if  required,  in  addition  to  the 

statutory  equipment : — 
25  lbs.  galvanised  anchor,  with  25  fathoms  of  3jV,  in.  galvanised 

chain. 
One   three-light  combination    light    (masthead,    port,  and 

starboard). 
One  small  rotary  pump  and  hose. 
One  chemical  fire  extinguisher. 
One  box  of  sand  with  scoop. 
Mechanical  syren. 

General  Requirements. — It  is  quite  beyond  the  intended 
scope  of  this  treatise  to  deal  in  detail  with  the  question  of  the 
internal  combustion  engine,  as  many  valuable  and  helpful  text- 
books have  already  been  written  on  the  subject. 


MOTOR  BOATS 

It  18,  therefore,  the  purpose  of  the  writer,  to  deal  only  with 
cei'tain  important  esaentiaifl  affecting  the  instaUation  of  petrol 
and  paraffin  engines  in  motor  Hfeboats. 

Before  construction  is  conunenced  on  the  hull,  there  ere 
certain  general  conditions  which  miiBt  be  strictly  observed. 

The  BcantUngH  and  full  detailed  specification  of  hull,  together 
with  particulars  of  machinery,  oil  tanks,  and  class  of  oil  to  be 
used,  must  be  submitted  to  the  Board  of  Trade  for  approval,  if 
the  lifeboat  is  to  form  part  of  the  statutory  equipment  of  a  vessel. 

It  is  considered  preferable  that  the  space  occupied  by  the 
mot«r.  fuel  tanks,  pipes,  etc.,  should  be  situated  at  the  after 
end  of  the  boat,  for  the  better  protection  of  the  passengers  or 
occupants. 

The  motor  space  is  separated  from  the  space  occupied  by  the 
passengers  or  crew  by  a  watertight  bulkhead.  In  the  particular 
case  where  the  engine  is  fitted  amidships,  and  the  majority  of 
^H  motor  launches  are  thus  arranged,  bulkheads  are  placed  at  each 
^F  end  of  the  motor  space,  and  made  watertight  to  at  least  the  height 
of  the  seats.  These  bulkheads  are  usually  made  oi  two  thick- 
nesses of  teak  or  mahogany,  with  a  calico  or  canvas  fabric  between, 
well  bedded  in  marine  glue  or  treated  with  boiled  linseed  oil  and 

1  white-lead  paint. 
Installation    of    Motor.— The  power  of   the  engine   must  be 
snitable  to  the  size  of  the  boat.     (Shipowners  have  often  stipulated 
a  speed  out  of  all  proportion,  which  has  practically  resulted  in  the 
building  of  a  boat  to  suit  the  ty|}e  and  weight  of  the  machinery, 
instead  of  making  proper  provision  for  the  accommodation  of  the 
occupants,  and  installing  an  economical  type  of  engine  poesesaiug 
a  reasonable  power  which  will  develop  a  speed  of  7  or  8  knots. 
A  30  B.H.P.  4-cyhnder  motor  installed  in  a  30-ft.  hfeboat 
gives  a  speed  of  about  7  knots.     A  20  B.H.P.  4-cyliuder  motor  in  a 
28-ft.,  and  a  12  B.H.P.  2-cylinder  motor  fitted  in  a  22-ft.  motor 
lifeboat  would  give  about  the  same  speed. 
To  secure  a  greater  speed  would  mean  the  titling  of  a  much 
larger  motor,  more  capacity  for  the  fuel  tanks,  greater  weight, 
and  a  smaller  number  of  passengers  accommodated. 
Particular  care  must  be  exercised  in  fitting  substantial  bearers 
under  the  engine,  well  secured  to  the  hull.     The  motor  should  be 
kept  as  low  as  possible  in  the  boat. 
The  cylinders  are  tested  by  water  to  twice  the  maximum 
working  pressure  to  which  they  will  be  subjected  under  service 
conditions,  and  the  silencer  and  the  exhaust  pipes  to  at  least 
one-fouith  of  the  pressure  apphed  to  the  cylinders. 


356  SH1P8'  BOATS  ^^^H 

Prevention  of  Oil  Leakage.^ — The  niotoi  standH  iii  a  metal  trsy,fl 
which  ia  forniwl  so  as  to  admit  of  being  readily  cleaned,  and  everyfl 
care  ahoidd  be  taken  by  the  fitting  of  suitable  drip  pans  where'l 
required,  to  prevent  the  woodwork  fiom  becoming  saturatod  I 
and  the  oil  spreading  through  the  bilges.  I 

The  floor  boards  are  made  portable  to  render  easy  access  to  I 
the  bilges  for  inspection.  M 

Receptacles,  fitted  with  wire  gauge  coverings,  are  provided.B 
to  catch  any  overflow  of  petrol  from  the  engine.  I 

The  greatest  safeguard  against  explosion  or  fire  is  cleonlinesS).! 
and  every  precaution  should  be  taken  when  installing  the  motor,  I 
to  see  that  the  woodwork  and  bilges  are  kept  free  from  oil  refuse..! 
All  tanks  and  a^tsociated  fittings  must  be  perfectly  tight.  I 

If  a  paraffin  tank  is  installed,  no  cocks  should  be  fitted  excepti 
for  the  motor  pipe  connections.  ■ 

Insulation. — It  may  be  necessary,  in  way  of  excessive  heatfl 
from  the  cylinder  heads  or  exhaust  pipe,  to  aheath  the  surround-l 
ing  woodwork  with  metal.  It  is  also  very  desirable  that  the! 
wooden  flooring  in  way  of  the  motor  should  be  sheathed  in  tbiSB 
manner.  I 

Carburettor. — Connected  to  the  cylinders  is  a  supply  pipftV 
leading  fi'om  the  carburettor.  The  function  of  the  carburettor,! 
briefly  explained,  ia  to  receive  the  petrol  from  the  fuel  tanki 
through  a  supply  pipe  fitted  to  the  bottom  of  the  float  chamberi! 
the  admission  of  which  is  regulated  by  a  needle  valve  having  mm 
spindle  connected  to  a  float.  I 

By  the  action  of  weight"  operating  on  the  float  and  valve,! 
fuel  is  alhiwed  to  enter  the  chamber  regularly  and  remain  at  aA 
constant  level.     Connected  to  the  float  chamber  is  a  pipe  witb^ 
a  jet,  situated  just  above  the  level  of  the  fuel,  which  is  led  into  a 
mixing  chamber,  and  as  soon  as  the  engine  is  started,  air  ia  drawn 
by  suction  into  the  mixing  chamber.     At  the  same  time  fuel  is 
drawn  from  the  jet  in  the  pipe  leading  from  the  float  chamber,.] 
and  in  association  with  air  it  becomes  vaporised  owing  to  ila 
volatility,  and  remains  so  during  its  passage  to  the  cylinders. 

The  proper  proportion  of  fuel  vapour  and  air  is  obviousljn 
very  important,  in  order  to  produce  the  best  results  from  th« 
point  of  view  of  economising  fuel  without  loss  of  power. 

The  controlling  of  the  mixture  in  suitable  proportions  fi 
the  basis  for  the  different  characteristics  of  the  many  useful  tyj 
of  carburettors  now  on  the  market. 

Carburettura  must  be  of  sucli  a  type  that  when  the  I 
is  8t<)pped  the  supply  of   petrol  to  the  carburettor  is  shut  ofij 


MOTOR   BOATS 


aiitomatically,  but,  iu  auy  case,  means  should  be  provided  to 
prevent  an  overflow  of  petrol  from  the  carburettor  into  the  boat. 
The  pipe  which  conveys  the  petrol  to  the  carburettor  is  solid 
drawn  copper,  and  provided  with  flexible  bends,  Iiaving  a  cock 
or  valve  fitted  at  each  end  of  the  pipe,  one  being  on  the  tank,  and 
the  other  on  the  carburettor  or  float  chamber.  All  joints  and 
couplings  are  made  so  aa  to  be  always  accessible  and  kept  oil- 
tight. 

Paraffln  Motors. — Petrol  motors  are  usually  fitted  to  the 
aniallest  type  of  motor  boats,  but  where  a  wider  radius  of  actiim 
is  necessary,  which  involves  a  larger  quantity  of  fuel,  the  installa- 
tion of  paraffin  engines  is  much  to  be  preferred.  The  latter  have 
the  advantage  of  using  a  fuel  which  possesses  a  much  higher 
flash  point  than  petrol,  and  is,  therefore,  not  so  liable  to  create 
danger  to  the  passengers, 

In  a  ship's  lifeboat  it  seems  essential  to  resort  to  the  necessity 
of  maintaining  a  small  supply  of  petrol  for  tlie  purpose  of  starting 
the  motor,  to  enable  the  boat  to  clear  from  the  ship  as  quickly  as 
possible,  instead  of  having  to  wait  until  the  cylinders  become 
heated  by  the  application  of  blow-lamps, 

In  petrol  motors  the  fuel  is  vaporised  at  ordinary  temperatures, 
being  verj'  volatile,  and  when  brought  into  contact  with  a  current 
of  air  created  by  the  suction  of  the  motor,  it  remains  in  a  condition 
of  vapour.  When  the  petrol  and  air  enter  the  cylinders  in  proper 
proportions,  they  form  together  an  explosive  mixture. 

Paraffin  will  not  remain  in  vapour  form  when  mixed  with 
cold  air,  beini;  not  bo  volatile  as  petrol,  and  it  becomes  neccasar\' 
to  arrange  for  the  fuel  to  be  sprayed  into  the  cylinders 
after  the  latter  have  become  heated,  or  to  bring  it  into  a 
gaseous  condition  before  entering  the  cylinders  by  means  of  a 


Petrol  is  first  appUed  to  start  the  engine  until  there  is  sufficient 
heat  created  in  the  exliaust  pipes  to  vaporise  and  bring  the 
paraffin  mixture  into  a  condition  of  combustion.  The  petrol 
supply  is  then  shut  oS,  and  the  motor  continues  running  on  the 
paraffin. 

Alternatively  the  inlet  pipe  or  vaporiser  can  be  heate<l  by 
blow-lamps  inserted  so  that  the  flames  pass  round  the  heating 
chambers  until  a  temperature  of  about  140°  F,  is  reached,  when 
the  conditions  are  such  as  to  allow  the  engine  to  start  and  to 
keep  running  by  the  action  of  the  heated  exhaust  vapour  from 
the  cylinder  around  the  walls  of  the  heating  chamber  of  the 
vaporiser. 


258  SHIPS'  BOATS 

A  28  B.H.P.  motor  takes  about  ten  minutes  to  heat  by  blow- 
lamps before  it  is  in  a  condition  for  starting.  The  flame  from 
the  blow-lamps  must  be  enclosed. 

Hot  Bulb  System* — Briefly  explained,  this  consists  of  a  bulb 
attached  to  the  cylinder,  which  is  heated.  The  paraffin  is 
then  sprayed  direct  into  the  interior  of  the  bulb,  an^  becomes 
vaporised.  There  is  a  valve  connection  to  the  bulb,  through 
which  air  is  drawn,  the  combination  of  air  and  vaporised  fuel 
producing  the  explosion.  The  size  of  the  bulb  depends  on  the 
compression  of  the  engine. 

Very  few  motor  launches  are  fitted  with  the  hot  bulb  system  ; 
it  is  practically  limited  to  vessels  which  are  run  for  commercial 
purposes. 

Sufficient  information  may  be  gathered  from  the  rough 
description  of  the  various  systems  in  operation,  to  feel  con- 
vinced that,  taking  the  circumstances  into  consideration,  a  power 
lifeboat  should  be  installed  with  a  paraffin-burning  motor,  but 
fitted  with  arrangements  for  starting  the  engine  on  petrol. 

Fuel  Tanks. — The  petrol  tank  must  be  large  enough  to  obviate 
the  necessity  of  carr}nng  a  supply  of  petrol  in  spare  cans.  It 
should  be  substantially  made  and  so  arranged  that,  when  being 
filled,  petrol  will  not  escape  and  find  access  below  the  deck. 

A  wire  gauze  diaphragm  is  fitted  to  each  inlet  and  outlet  of 
the  fuel  tank,  made  in  such  a  manner  as  to  be  easily  removed  for 
cleaning  and  inspection. 

The  open  end  of  the  inlet  pipe  is  led  to  the  atmosphere  above 
the  deck,  as  the  air- and  gas  displaced  when  filling  the  tank  may 
be  an  explosive  mixture. 

A  feature  in  connection  with  the  motor  and  all  its  accessories 
is  that  all  the  pipes  and  fittings  must  be  perfectly  tight,  to  prevent 
the  escape  of  petrol  gas. 

If  the  oil  tank  is  of  iron  or  steel  it  is  galvanised  and  usually 
tested  by  water  to  a  pressure  corresponding  to  a  head  of  water 
of  at  least  fifteen  feet. 

The  fuel  tank  in  small  motor  boats,  and  in  boats  fitted  with 
petrol  tanks  for  starting  purposes,  is  arranged  at  a  convenient 
li(»4ght  to  allow  the  supply  pipe  to  have  an  easy  lead  and  give  a 
steady  and  constant  delivery  by  the  force  of  gravity.  Where 
the  horse-power  of  the  engine  is  great  and  the  radius  of  action 
of  the  motor  boat  is  large,  then  it  becomes  necessary  to  carry  an 
increased  (jiiantity  of  fuel. 

It  is  essential  from  the  point  of  view  of  stability,  that  all 
weiglits  should  l)e  carried  as  low  as  possible  in  the  boat,  therefore 


MOTOR  BOATS 


^^Rtt  is  advisable  to  keep  the  fuel  tank  well  down  below  the  deck 
^^  ends,  and  in  these  circurastancea  it  is  an  advantage  to  fit  a  system 
of  forced  feed,  or  a  means  of  supplying  fuel  to  the  carburettor 
under  pressure. 

Water  Cooling.— Water  is  pumped  into  the  cylinder-jackets  for 

■  cooling  purposes.     It  is  essential  that  care  should  be  exercised 

I  when  deciding  on  the  position  of  the  water  inlet  pipe  in  order  to 

[  preserve  a  constant  supply  through  easy  leads,  and  that  the 

intake  is  never,  at  any  time,  out  of  the  water. 

It  is,  of  course,  necessary  to  fit  a  strainer  at  the  inlet  to  prevent 
weeds  choking  the  supply  pipe,  and  also  a  seacock  close  down  to 
'  the  hull. 

The  exhaust  pipe,  which  carries  away  the  discharged  vapour 
\  from  the  cylinders,  becomes  very  hot,  owing  to  the  gas  reaiaining 
at  a  very  high  temperature.  With  a  wooden  lifeboat  this  becomes 
irious  consideration,  and  effective  means  should  be  pnivided 
for  water-cooliug  or  lagging  the  exhaust  pipes,  which  are  led  out- 
board above  the  water-line  or  down  through  the  bottom  of  the 
boat,  and  the  gases  discharged  into  the  water. 

Reverse  Gear.^ Adequate  provision  is  made  to  allow  the  boat 
to  go  astern.  Sometimes  the  arrangement  simply  conaista  of 
reversing  propellers,  the  action  of  which  is  to  reverse  the  piteh 
of  the  blades,  but  maintaining  the  same  direction  of  rotation. 

The  usual  practice  is  to  supply  a  gear  actuated  by  a  clutch 
which  directly  alters  the  rotation  of  the  shaft.  There  are  many 
satisfactory  types  uf  reverse  gear  now  on  the  market. 

ISnlflon-^The  greatest  enemy  tfl  the  internal  combustion 
engine  is  r2am/>.  The  ignition  fittings  and  wires  must  therefore  be 
,  efficiently  protected  from  moisture,  to  enable  theoi  to  be  of 
I  service  after  a  period  of  disuse.  The  machinery,  or  engine, 
,  must  be  closed  in  or  properly  protected  from  the  weather  and 
L  spray. 

When  the  vaporised  mixture  of  fuel  and  air  has  been  com- 
I  pressed  by  the  action  of  the  pistims  in  the  cylinders,  the  explosion, 
or  power  which  drives  the  engine,  is  produced  by  aa  electric  spark 
generated  by  an  electric  battery,  or  accumulators,  and  an  induc- 
tion coil,  or  by  what  is  now  universally  used,  a  magneto. 

The  feature  of  the  induction  coil  is  to  transform  the  low 
r  volta^  current  of  the  accumulators  to  a  high  voltage  in  order  to 
I  produce  the  electric  spark  for  ignition  purposes. 

The  distance  between  the  terminals  through  which  the  spark 
I  jumps,  is  termed  the  spark  gap.  Mechanical  means  are  fitte<l 
rnnTk  the  caiushaft  so  as  to  make  contact  with  the  switch,  and 


SHIPS'  BOATR 


piodnce  s  spsrk  st  the  correct  oiotneDt  for  the  ignitMia 
oompresaed  vapour  in  tJie  cylinder. 

The  magneto  is  practicallj  a  snutU  dynamo  ot  medumical 
means  of  gaierating  eleMricity,  instead  of  with  the  aid  of 
chemicaU. 

Sometimes  a  combination  of  the  two  systems  is  used,  the 
accumidatoiB  being  fitted  for  the  purpose  of  starting  the  engine. 

With  the  high  tension  system  of  ignition,  there  is  alwa^-s  tie 
danger  of  leakage,  and  all  wiring  must  be  ven,-  carefully  initiated 
and  protected  from  moiHture. 

Where  the  wires  are  led  into  the  cylinder  to  produce  the 
ignition  spark,  there  is  fitted  what  is  termed  a  gpark  plfig.  which 
provides  proper  protection  to  the  wires,  enables  them  to 
withfltand  the  effect  of  the  explosion,  and  give  the  necessary 
amount  of  insulation. 

Lnbrle&tlon.— The  question  of  a  satisfactory  means  of  hibri- 
eating  the  bearing  surfaces  of  the  machinery  is  one  of  importance, 
owing  to  the  speed  of  the  motor  and  the  generation  of  a  very  high 
temperature. 

One  system  is  by  the  supply  of  oil  to  the  crank  case,  and  the 
action  of  the  rotating  connecting  rods  simply  splashes  the  oil 
over  the  various  bearings.  This  method  can  only  be  considered 
successful  when  the  motor  engine  is  kept  nearly  level  with  the 
water-line.  In  the  majority  of  cases  the  cylinders  are  inclined, 
and  it  then  becomes  necessarj'  to  fit  the  ordinary  drip  or  pressure 
feed  systems. 

VBntilatlon.^\Vhen  the  motor  or  the  petrol  tank  is  situated  in 
an  enclosed  space,  special  precautions  should  be  taken  to  pro\'ide 
an  efficient  means  of  ventilation,  by  the  fitting  of  cowls  or  other 
suitable  ventilators,  one  of  which  should  be  carried  down  to  the 
lower  part  of  the  enclosed  space.  The  combination  of  the  two 
ventilators  will  prevent  the  accumulation  of  oil  vapour  in  the 
lower  part  of  the  boat. 

Fire  ExtingulaUng  Appliances.— Reference  has  aheady  been 
made  in  Section  B  of  Part  III,,  to  the  use  of  non-infiammable 
wood  in  connection  with  the  construction  of  the  bearers  or 
seating  for  the  motor,  and  the  covering  casing. 

The  general  expression  of  opinion  is  that  this  particular 
wood  serves  its  purpose  well,  and  its  incorporation  into  the 
structure  is  certamly  a  precautionary  means  against  the  spread 
of  fire. 

It  is  usual  to  provide  one  or  two  chemical  fire  extinguishers, 
tlie  number  depending  on  the  size  of  the  boat.     These  are  fitted 


MOTOK  BOATS  261 

ia  a  rack  near  tho  eugiue  ready  £or  mime«liiitb__iiBe.  In  additiun 
to  the  extinguisliers,  a  box  of  sand  not  less  than  one  cubic  foot  in 
capacity,  is  provided  together  with  a  suitable  scoop  for  applying 


General  Remarks, ^The  quality  and  size  of  tho  shaft  have 
to  be  considered  in  relation  to  the  power  of  the  motor,  and  this 
is  a  point  which  rnuat  be  given  due  prominence  in  the  specification, 
as  the  Board  of  Trade  oSicials  may  consider  it  is  too  small,  and 
if  construction  on  the  stempOst  and  deadwood  has  commenced, 
then  there  is  trouble.  The  shaft  is  tested  for  ductiUty  and 
tensile  strength  ;  it  is  usually  made  of  phosphor  bronze. 

Particular  att«ntion  must  be  paid  to  the  Heatings  of  the  engine, 
gear  box,  and  thrust  block,  in  order  to  preserve  the  ahgmnent  of 
shaft.  It  iH  of  the  utmost  importance  that  the  first  consideration 
should  be  the  strength  of  the  fiadie  combinations  to  prevent  any 
movement  when  the  boat  is  subjected  to  hogging  and  sagging 
stresses  from  wave  motion.  There  is  constant  difficulty  to  secure 
a  smooth  running  engine  if  the  foundation  or  seating  is  insecure. 
In  this  respect,  from  the  writer's  point  of  view,  it  is  an  undoubted 
advantage  t<i  the  boat  when  the  firm  constructing  the  hull  is  at 
the  same  time  able  to  build  and  instal  the  motor.  The  trades  are 
quite  separate  and  distinct,  but  many  difficulties  are  often 
avoided  when  the  engineers  are  given  the  opportunity  to  cany 
through  the  installation;  the  opinions  of  both  trades  are 
necessary  to  secure  the  best  results. 

The  best  of  material  may  be  worked  into  the  construction 
and  the  highest  standard  of  workmanship  brought  into  operation, 
in  fitting  out  a  motor  lifeboat  with  all  the  latest  and  most  efficient 
appliances  for  propulsion,  but  unless  constant  care  is  exercised 
in  periodically  overhauling,  lubricating,  and  keeping  the  motor  in 
trim,  while  the  boat  ia  in  service  on  board  a  vessel,  the  value  of 
the  launch  as  a  life-saving  appliance  is  very  small. 

The  danger  of  neglect  would  be  more  pronounced  in  the 
case  of  a  "  power  '  than  in  an  ordinary  pullmg  boat,  hence  the 
hesitation  on  the  part  of  some  people  to  limit  the  number  of 
motor  boats  on  a  large  passenger  vessel. 

The  equipment  supplied  to  a  motor  lifeboat  is  the  same  as 
that  appropriated  to  a  Class  I.  open  lifeboat,  except  that  sails 
may  be  dispensed  with,  and  as  it  is  usual  to  fit  a  proper  rotary 
or  plunger  pump  tor  keeping  the  bilges  throughout  the  length 
of  the  boat  free  of  water,  it  seems  unnecessary  to  supply  the  bailer 
as  detailed  in  the  instructions. 


I 


LLOYD'S    RULES     FOR    THE    SURVEY    OF    INTERNAL    COM- 
BUSTION  ENGINES  (OTHER  THAN  OF  THE  DIESEL  TYPE) 


GENERAL. 

Section  1. — In  vessels  propelled  bv  internal  combustion  1 
engines  the  rules  as  regards  machinery  will  be  the  same  as  those  I 
relating  to  steam  engines,  so  far  aa  regards  the  testinf{  of  material  1 
used  in  their  construction,  and  the  fitting  of  sea  connections,  I 
discharge  pipes,  shafting,  stem  tubes,  and  propellers  ai 
concerned. 

CONSTRUCTION. 

fiection  '2. — 1.  The  following  points  tdiould  be  observed  i 
connection  with  the  design  of  the  engines ; — 

2.  The  shaft  bearings,  connecting-rod  brasses,  the  valve  gear,  i 
the  inlet  and  exhaust  valves  must  be  easily  accessible.  1 

3.  The  reversing  gear  and  clutch  must  be  strongly  constructed  I 
and  easily  accessible  for  examination  and  adjustment, 

4.  In  engines  of  above  60  B.H.P..  which  are  not  reversible,  ] 
and  which  are  manoeuvred  by  clutch,  a  governor  or  other  arrange-  I 
ment  must  be  fitted  to  prevent  racing  of  the  engine  when  I 
declutched, 

0.  Efficient  positive  means  of  lubrication  (preferably  sight  J 
feed)  must  be  fitted  to  each  part  requiring  continuous  lubrication,  1 

(i.  If  the  engines  are  of  the  closed-iu  type  they  must  be  ra  I 
fitted  that  the  contained  lubricating  oil  can  be  drained  when  I 
necessary,  and  in  wood  vessels  an  easily  drained  metal,  or  metal'l 
hned,  tray  must  be  fitted  to  prevent  leakage  of  either  fuel,  oil,  or  j 
of  lubricating  oil  from  saturating  the  woodwork. 

7.  Carburettors,  where  petrol  is  used,  and  vaporisers,  whcrftl 
paraffin  is  used,  should  be  so  designed  that  when  the  engine  IB  l 
stopped  the  fuel  supply  is  automaticAllyshut  olf.     If  an  overflow 
IB  provided  in  the  carburettor  or  vaporiser,  a  gauze-covered  tray, 
with  means  of  draining  it.  must  be  fitted  to  prevent  the  fael 
from  Sowing  into  the  bilges. 

Strong  metallic  gauze  diaphragms  should  be  fitted  eitltei,1 
between  the  carburetter  (or  vaporiser)  and  cylinders,  or  at  thfl  J 
air  inlets. 

8.  If  the  ignition  ia  electric,  either  by  magneto  or  by  coil  and^ 
accumulator,  alt  electric  leads  must  be  well  insulated  and  snitably  J 
protected  from  mechanical  injury.     The  leads  should  be  I 


MOTOR   BOATS  263 

remote  from  petrol  pipes,  and  should  not  be  placed  where  they 
may  be  brought  into  contact  with  oil. 

The  commutator  must  be  enclosed ;  and  the  sparking  coils 
must  not  be  placed  where  they  can  be  exposed  to  explosive 
vapours. 

9.  No  exposed  spark  gap  should  be  fitted. 

10.  In  paraffin  and  heavy  oil  engines,  where  lamps  are  used 
for  ignition  or  for  vaporising,  these  lamps  should  be  fixed  by  some 
suitable  bracket,  and  the  flame  enclosed  when  in  use. 

11.  The  circulating  pump  sea  suction  is  to  have  a  cock  or 
valve  on  the  vessel's  skin,  placed  on  the  turn  of  the  bilge  in  an 
easily  accessible  position,  and  the  circulating  pipe  is  to  be  pro- 
vided with  an  efficient  strainer  inside  the  vessel.  The  discharge 
overboard  is  to  be  fitted  with  a  cock  or  valve  on  the  vessel's  skin, 
if  it  is  situated  under  or  near  the  load-line  of  the  vessel. 

12.  The  pumping  arrangements  are  to  be  the  same  as  would 
.be  required  in  the  case  of  a  steam  vessel  of  the  same  size  and 
power,  with  the  except i(m  that  no  bilge  injection  need  be  fitted. 
In  the  cases  of  vessels  fitted  with  water  ballast,  the  water  ballast 
pump  must  have  one  direct  suction  from  the  engine-room  bilges 
in  addition. 

In  open  launches,  and  in  small  sailing  vessels  in  which  the 
engines  are  auxiliary  only,  a  suitable  additional  hand  pump, 
fitted  to  draw  from  the  engine-room  bilges,  may  be  accepted  in 
lieu  of  a  power-driven  pump. 

13.  The  cylinders  are  to  be  tested  by  hydraulic  pressure  to 
twice  the  working  pre>ssure  to  which  they  will  be  subjected.  The 
water-jackets  of  the  cylinders  to  50  lbs.  per  sq.  in.,  and  the 
exhaust  pipes  and  silencer  to  100  lbs.  per  sq.  in. 

14.  The  exiiaust  pipes  and  silencer  should  be  efficiently  water 
cooled  or  lagged  to  prevent  damage  by  heat,  and  if  the  exhaust  is 
led  overboard  near  the  water-line,  means  must  be  arranged  to 
prevent  water  from  being  syphoned  back  to  the  engine. 

15.  The  machinery  must  be  tried  under  full  working  C(m- 
ditions,  the  report  stating  the  approximate  speed  of  vessel,  the 
number  of  revohitions  of  the  engines  at  full  power,  both  ahead 
and  astern,  and  the  lowest  number  of  revolutions  of  the  engines 
which  can  be  maintained  for  manoeuvring  purposes. 

RULES  FOR  DETERMINING  SIZES  OF  SHiVFTS. 

Section  3. — The  crank,  intermediate  and  other  shafts,  if  of 
mild  steel,  are  to  be  of  not  less  diameters  than  as  given  in  the 


264 


SHIPS    BOATS 


followin;;^  table.     When  special  steel  is  used,  the  sixes  are  to  be 
submitted  for  consideration. 

1 .  For  petrol  or  parafiBn  engines  for  sniooth-water  services : 

Diameter  of  crank   | 

shaft  in  inches      i  ~  ^^  ^'^ 

where  D  =:  diameter  of  cylinder  in  inches. 
S  =:  stroke  of  piston  in  inches. 


Four-stpjke  cycle. 

T»u-iii 

Lroke  cycle. 

eachcrmnk. 

the  bemrinss. 

For  1,2,  3  or  4  C vis. 

1  OI 

2  Cyls. 

c=a4 

C- -38 

»f                    ^     .. 

3     „ 

C  =  -36 

C  =  -40 

»»                    8     »f 

4     „ 

C  =  -38         ! 

C  =  -426 

12     „ 

6     „ 

C  =  -44 

C  =  -49 

For  open-sea  service  add  '02  to  C. 

Diameter  of  intermediate  and  j  _ri^T)*>a/ "X  o\ 
screw  shafts  in  inches  ( ~"  V     •     / 

where  D  =  diameter  of  cylinder  in  inches. 
S  =stroke  of  piston  in  inches, 
n  =  number  of  cylinders. 


For  smooth-water  services. 

For  open-sea  seryices. 

C  s  '155  for  intermediate  shafts 

C       170     /  ^^^  screw  shafts  fitted  with  continaous  \   , 

\       liners                                                        /  ' 
0=**180     }  ^^^   screw    shafts    fitted   with   separate^ 

)       liners  or  with  no  liners                             J 

C  «  166 
C=180 

C=190 

In  engines  of  two-stroke  cycle,  n  is  to  be  taken  as  twice  the 
number  of  cylinders. 

2.  When  ordinary  deep  thrust  collars  are  used,  the  diameter 
(){  the  shaft  between  the  collars  is  to  be  at  least  |(\ths  of  that 
of  the  intermediate  shaft. 

3.  The  above  rules  apply  only  to  engines  in  which  the  initial 
pressure  does  not  exceed  250  lbs.  per  sq.  in.  In  the  cases  of 
semi-Diesel  and  other  engines  in  which  higher  initial  pressures 
are  employed,  particulars  should  be  submitted  for  special 
consideration. 


MOTOR   BOATS  265 

FUEL  TANKS  AND  CONNECTIONS. 

Section  4. — 1.  Separate  fuel  tanks  are  to  be  tested  with  all 
fittings,  to  a  head  of  at  least  15  ft.  of  water.  If  pressure  feed 
tanks  are  employed,  they  are  to  be  tested  to  twice  the  working 
pressure  which  will  come  on  them,  but  at  least  to  a  head  of  15  ft. 
of  water.  If  the  tanks  are  made  of  iron  or  steel  they  should  be 
galvanised. 

2.  Strong  and  readily  removable  metallic  gauze  diaphragms 
should  be  fitted  at  all  openings  on  petrol  tanks. 

3.  Paraffin  or  heavy  oil  tanks,  not  used  under  pressure,  are 
to  be  fitted  with  air  pipes  leading  above  deck.  Pressure-feed 
tanks  and  tanks  containing  petrol,  should  be  provided  with  escape 
valves  discharging  into  pipes  leading  to  the  atmosphere  above 
deck.  The  upper  ends  of  all  air  pipes  are  to  be  turned  down,  and 
pipes  above  1  in.  diameter  are  to  be  provided  with  gauze  dia- 
phragms at  the  end. 

4.  No  glass  gauges  are  to  be  fitted  to  fuel  tanks  containing 
either  petrol,  paraffin,  or  heavy  oil. 

5.  Filling  pipes  are  to  be  carried  through  the  deck  so  that 
the  gas  displaced  from  the  tanks  has  free  escape  to  the  atmosphere. 

6.  Separate  fuel  tanks  should  be  provided  with  metal-lined 
trays  to  prevent  any  possible  leakage  from  them  flowing  into  the 
bilges,  or  saturating  woodwork.  Arrangements  are  to  be  pro- 
vided for  emptying  the  tanks  and  draining  the  trays  beneath 
them.  For  petrol  tanks  the  trays  must  have  drains  leading 
overboard  where  possible,  or  they  should  be  gauze-covered  trays 
with  means  for  draining  them. 

7.  All  fuel  pipes  are  to  be  annealed^  seamless  copper  with 
flexible  bends.  Their  joints  are  to  be  conical,  metal  to  metal. 
A  cock  or  valve  is  to  be  fitted  at  each  end  of  the  pipe  conveying 
the  fuel  from  the  tank  to  the  carburettor  or  vaporiser.  The  fuel 
pipes  should  be  led  in  positions  where  they  are  protected  from 
mechanical  injury,  and  can  be  exposed  to  view  throughout  their 
whole  length. 

8.  The  engine-room,  and  the  compartment  in  which  the  fuel 
tanks  are  situated,  are  to  be  efficiently  ventilated. 

9.  An  approved  fire-extinguishing  apparatus  must  be  supplied. 

PERIODICAL  SURVEYS. 

Section  5. — 1.  The  machinery  is  to  be  submitted  to  survey 
annually.    At  these  surveys  the  cylinders,  pistons,  connecting-rods, 


SHIPS'  BOATS 

Vnak  aiid  other  shafte,  inlet  aud  exhaust  valves  and  gear, 
«Jutches,  reverfiing  gear,  propeller,  sea  counections,  and  pumpe, 
are  to  be  examined.  The  electric  ignition  is  to  be  examined 
(and  the  electric  leads  tested.  The  fuel  tanks  and  all 
Connections  are  to  be  examined,  and  if  deemed  necessary-  by  the 
•urveyor,  to  be  tested  to  the  same  presHure  as  required  when  new. 
If  practicable,  the  engines  should  be  tested  under  working 
conditions. 

2.  The  Hcrew  shaft  is  to  be  drawn  at  intervals  of  not  more 
,  than  two  years. 

SECTION    B.— NESTED   BOATS 

General  Desorlption. — By  the  terms  of  General  Rule  12  of  the 
Lifp-aaviug  Appliances  Rules  (1914),  additional  lifeboats  may  be 
stowed  in  tiers  of  two  or  three  one  above  another,  or  they  may, 
subject  U}  such  conditions  as  the  Board  of  Trade  may  impose, 
be  fitted  one  within  another. 

Captain  P.  D.  Murray,  of  Liverpool,  has  bad  an  extensive 
experience  with  the  Mercantile  Marine  Service,  having  served 
in  sailing  aud  steam  vessels  for  21  years  at  aea,  and  was  marine 
superintendent  of  two  Atlantic  steamship  companies  [or  another 
21  years. 

The  ninkiui^  of  the  R.M.S.  Titanic,  as  the  result  of  a  collision 
with  an  iceberg,  prompted  Captain  Murray  to  endeavour  to  con- 
struct ordinary  open  lifeboats  of  Class  I.  of  sufficient  strength 
so  as  to  "  nest "  one  or  more  boats  within  another,*  and  thua 
provide  accommodation  for  all  persona  on  board  the  largest 
passenger  vessels,  which  would  include  the  crew  in  addition  to 
the  fuU  number  of  passengers. 

Theae  particular  boats  designed  by  Captain  Murray  form  tlie 
subject  of  the  present  section. 

For  classification  purposes  they  are  treated  as  Class  1a  open 
lifeboats,  but  they  differ  from  the  ordinary  Ufeboata  in  that  the 
thwarts  are   movable,  not  portable,  and  made  to  hinge  to  one 

The  boats  are  constructed  of  wood  of  the  best  materials  and 
workmanship. 

Fig.  149  shows  the  general  stowage  of  tliree  of  the«e  patent 
boats  in  a  nest. 

For  the  purpose  of  nesting,  the  thwarto  of  the  two  lower  boat« 
are  hinged  to  the  side  of  the  boat,  and  to  secure  the  necessary 
strength  for  sustaining  the  upper  boat,  a  fore  and  aft  stringer  is 


NESTED  BOATS  2C7 

fitted  around  the  inside  of  the  boat  on  a  hne  with  the  tliwarts, 
strengthened  by  galvanised  steel  angle  bars  secured  throiy^h  the 
foie  and  aft  stringer,  planking,  stem,  and  stempost.  By  fitting 
t^ree  or  more  deep  frames  connecting  from  the  deep  keelson  and 
extflodiog  to  the  fore  and  aft  etringers,  the  boat  is  well  tied 
together  both  in  a  longitudinal  and  in  a  transverse  direction. 
These  web  frames  are  strengthened  by  angle  bars  fitted  in  one 
piece,  following  the  line  of  the  upper  edge  of  deep  frames 
across  the  keelson,  and  secured  to  the  fore  and  aft  angles  and 
keelson. 

A  deep  keebon  is  fitted  in  one  continuous  length,  made  from 
pitch  pine  and  forms  a  good  stiff  backbone  to  support  the  weight 


¥m.  1411.  -KiTtii.ii  shtiwing  st<)uiij?3  u(  Ciijitjiiii  -Mumiys  nunted  lifcb"nl«. 

of  the  upper  buat.  .A  recess  is  provided  for  the  keel  of  the  upper 
boat  to  rest  on  the  keelson,  by  forming  fore  ami  aft  scats,  resting 
on  the  deep  frairie-s.  and  extending  the  full  leugth  on  both  sides 
of  the  boat.  Two  additional  fore  an<l  aft  seats  are  fitted  above 
the  lower  ones  so  that  seating  accommodation  below  the  thwarts 
is  provided  for  about  half  tlie  number  the  boat  is  certified  to 
carry,  which  ensures  greater  stability,  and  freedom  for  the 
rowers  at  the  thwarts. 

The  side  stringers  and  thwai-ts  provide  seating  accommodation 
for  the  remainder  of  tJie  persons  carried. 

The  space  betwet^n  the  fore  and  aft  stringers  and  the  lower 
edge  of  the  side  seats,  around  the  sides  of  the  boat,  provide  ample 
space  for  the  rojuired  volume  of  buoyancy  air-cases,  viz.  :   one 


268 


SHIPS'  BOATS 


cubic  foot  for  every  ten  cubic  feet  of  boat  capacity  obtained  bv 
Stirling's  Rule.  •  . 

The  air-cases  are  of  special  design,  giving  the  greatest  buoyancy 
at  the  bilge  of  the  boat. 

Under  the  seats  on  each  side  of  the  keelson  is  provided  stowage 
for  water  and  biscuit  tanks,  and  in  a  locker  fitted  aft  are  placed 
the  Uquid  compass,  distress  signals,  etc. 


(  t  ■■ 

Mouse**-  -^  "8>V^' 


/ 

\e LEGATION  or 

j  MODiriED  NOQH  B 


-    PLAN  or  SHACMLF 

rm. 


CHAIf\t 


SHACHl  I 


-  PLAN  - 


OETAtL     Of 


OA/f 


Fia.  150. — Details  of  lifting  gear  for  nested  lifeboat. 


The  space  between  the  seats  in  the  bottom  of  the  boat  provide 
stowa<^e  for  oars,  mast,  sails,  and  full  equipment. 

Foui-  hinged  thwarts  are  provided  for  oarsmen,  double  banked, 
and  supplied  with  special  fittings  to  permit  of  stowing  the  thwarts 
on  edge  on  top  of  the  fore  and  aft  stringer,  when  the  boats  are 
nested. 

The  general  arrangement  of  a  nest  of  lifeboats  is  shown  in 
Fig.  151,  wliich  indicates  the  positions  of  the  thwarts. 

As  the  upj)er  boat  is  launched,  the  thwarts  are  placed  across 
the  second  boat  and  secured  on  opposite  sides  by  cleats,  ready  for 


NfeSTBD   BOATS 


F¥^- 


^e  use  of  the  oarsmen.     The  boat  is  then  in  a  condition  for 
launching. 


270 


SHIPS'  BOATS 


The  Banie  procedure  is  tAkea  when  preparing  the  t^iid  i 
last  boat. 

In  a  nest  of  three  lifeboats,  the  lower  two  boata  are  con-  I 
atnicted  in  accordance  with  the  details  described,  but  the  top  1 
boat,  havinj;  fixed  thwarts,  is  biiilt  in  exactly  the  same  way  as  j 
an  ordinary'  pulling  boat  of  Class  Ia.  and  fitted  with  jfarrf  lifting-  I 
hooks. 

Slings  are  fitted  for  carrying  the  lifting-hook  for  attachment 
to  the  da^Ht  blocks.  They  are  well  secured  to  the  keelson  and  deep  1 
frame  at  each  end  of  the  boat.  Connection  is  also  made  to  an  eye-  j 
plate  welt  secured  to  the  stem  and  stempost,  as  shown  in  Fig.  160.  1 
The  hook  ia  steadied  by  guy  chains  secured  to  eye-bolts  in  the  j 
fore  and  aft  stringers,  and  attached  by  clip  hooks  on  the  oppoaito  I 
aide  to  which  the  sling  chain  is  secured  to  the  keelson  ;  so  that  7 
by  unhooking  this  guy  chain,  the  sling  will  drop  clear  of  the  top  J 
of  the  keelson  from  its  secured  position.  I 

When  the  upper  boat  is  launched,  it  is  only  necessary  to  hook  "I 
on  this  guy  chain,  adjiist  the  thwarts,  and  the  second  boat  ia 
then  ready  for  lifting. 

Nests  may  consist  of  two  or  three  hfeboats.  A  nest  of  three! 
would  consist  of  boat«  of  the  following  dimensions  : — 

No.  1.  260'  X  68'  X  30'  accommodating  35  persons 
No.  2.  280'  X  8-2'  x  36'  „  56       „ 

No.  3.  300'  X  9-8'  X  4-2'  ,.  82       „ 

Total  accommodation  in  one  nest  =  173  persons.     Neets  of  ^ 
28  ft.,  26  ft.  and  24  ft.  boats  are  provided,  if  desired,  to  suit  the 
requirements  of  the  deuk  space  on  board. 

Nested  boats  can  be  placed  under  any  davits,  provided  suffi- 
cient hoist  b  given  for  launching  the  two  inner  boats  from  the 
outer  one,  and  allowing  the  keels  to  clear  the  gunwale  of  the  boat 
that  is  sitting  in  the  chocks.     A  drift  of  about  10  ft.  is  considered 


The  photograph  shown  at  Fig.  153  shows  the  adaptability  of 
Messrs.  Babcock  and  Wilcox's  patent  long-reach  davits  to  suit 
the  requirements  of  these  nested  boats.  Boat  chocks  are  only 
required  for  the  lower  boat,  each  nested  boat  having  its  keel  resting 
on  iha  keelson  of  the  lower  boat.  When  the  three  boats  are 
secured  in  their  correct  stowing  positions,  the  total  depth  formed 
by  the  keels  and  keelsons  amotmts  to  3  ft.  C>  in.,  providing  a 
girder  which  helps  to  distribute  the  weight  and  prevents  deflecUon. 

Only  one  set  of  gripes  is  required,  fitted  in  the  usual  manner 
to  the  lower  boat  with  slip  liiiku  on  each,  and  extensinn  gripes  a 


NESTED  BOATS 


271 


carried  up  to  the  middle  and  upper  boats,  security  being  made  by 
lanyards.  Thus  each  boat  is  kept  in  its  relative  position,  un- 
afiected  by  the  rolUng  of  the  ship,  permitting  the  gripes  o[  each 
boat  to  be  detached  in  rotation  as  the  boats  are  launched. 

In  an  emergency,  by  disconnectii^  the  slip  hnks  to  the  lower 
boat,  all  three  boate  are  free  to  float  away. 

One  canvas  cover  protects  all  three  boats  of  the  neat,  and  the 
spar,  which  is  placed  between  the  lower  blocks  of  the  davit  to 
prevent  the  tackles  from  becoming  "  cable  laid  "  and  ffJuHiit;  after 
launching  the  first  or  second  boats  when  rounding.'  up  the  falls. 


I 


Murray's  oestod  lifebo»tB. 

serves  the  purpose  also  of  a  ridge  spar  to  take  the  canvas  cover. 
The  latter  is  laced  in  the  usual  manner  under  the  rubbers  of  the 
lower  boat. 

The  system  of  neatint;  Ufeboats  has  several  advantages  which 
appeal  to  some  shipowners,  the  most  important  of  which  is  that 
the  boats  are  stowed  imiaedjately  under  davit«,  thus  dispens- 
ing with  the  necessity  of  fitting  transporting  gear  to  bring  boats 
stowed  inboard  to  the  ship's  side.  It  is  further  contended  that 
a  conaidferable  saving  of  time  is  effected. 

It  may  also  be  mentioned  that  Captain  Murray  lias  made 
another  improvement  in  the  type  of  lifting-hogk  fitted  to  the 
chain  slings.     .\  departure  has  been  made  &oni  the  plan  shown 


272  •  SHIPS'  BOATS 

at  "A  "  in  Fig.  150,  and  a  new  arrangement  subBtituted  as  at 
"  B."  When  the  tackle  falls  are  slacked  for  the  purpose  of  un- 
hooking the  boat,  the  hook  is  kept  fairly  upright  by  the  steadyinj^ 
chains.  Aa  the  boat  becomes  water-borne  the  locking  arrange- 
ment is  relieved  and  operated  by  a  Bmiill  cord  attached  under 
the  point  of  the  hook  when  locked,  and  at  the  lowest  point  when 
open.  The  action  of  the  horn  on  the  hook  prevents  the  link  of 
suitable  size  on  the  tackle-block  from  moving  in  any  direction  but 
towards  the  point  of  the  hook,  and  will  thus  cause  detachment. 


Fid.   153.— Nested  lileboatB  under  Biibcock 


The  mousing  arrangement  prevents  the  falls  from  detaching 
themselves  from  the  hook. 

A  complete  set  of  Captain  Murray's  patent  nested  boats  is 
iUustrated  in  Fig.  152.  The  photograph  was  taken  in  the  boat 
yard  of  Messrs.  Qouk  and  Nesbit,  Glasgow. 

Before  this  principle  of  constructing  nested  borfta  was 
accepted  by  the  Board  of  Trade,  very  detailed  and  extended 
testa  were  earned  out  in  Liverpool,  und«r  service  conditiona. 
It  will  serve  no  useful  purpose  to  refer  to  these  teste  in  any  detail, 


SUKF  BOATS 


273 


but  briefly,  they  were:  (1)  Strength;  (2)  Stability;  (3)  Freeboard 
and  Flooduif; ;  (4)  Laimchinj; ;  (5)  Seating;  and  Rowing. 

It  is  of  intereiit  t(i  note  that  with  reference  to  test  No.  3,  the 
buoyancy  tanks  were  removed  from  the  3l"^ft.  lifeboat,  the  plu>; 
waa  removed  and  the  boat  filled  with  water.  She  remained  in 
that  condition  for  21  hours,  the  freeboard  rau^dnf;  from  H  to 
5  in.,  dpnionatratinii  that  t!ie  boat  will  more  than  support  the 
steel  anyles  and  ironwork  used  iu  the  constmction. 

No.  4  test  only  oc^cnpied  l(i  minutes,  the  three  boats  being 
laimchefl  in  that  time  from  the  deck  of  the  R.M.S.  VKtorian  in 
the  Canada  Dock.  Liverpool. 

It  may  also  be  of  interest  to  mention  that  one  boat  of  a  neat 
on  .1  liner,  torpedoed  some  230  miles  off  the  Fastnet,  was 
picked  up  two  monthB  later  in  good  condition  ofi  the  Clate  Coast 
of  Ireland. 

Donble-skin  boats  are  aupplieil  to  vessels  sailing  to  the  tropica, 

where  the  single  thickness  will  not   stand   the  excessive  heat 

and  remain   watertight.      The  double  thickness  will   ensure  a 

"  tight "'  boat,  and  is  made  with  outside  plaiikiny  of  oak  and 

aide  of  larch,  having  a  layer  of  oiled  calico  placed  between  the 

|j.8kins, 

SECTION  C— SURF  BOATS 

^il«n«tal   Description. — Siu'f   boats   are  constructed  to   meet  the 

iquirements  of  vessels  engaged  in  a  particular  trade. 

It  is  impossible  for  ordinary  pulling  boats  to  be  utilised  along 

bain  parts  of  the  West  Coast  of  Africa,  and  a  large  portion  of 

2ie  cargo  has  to  be  transported  from  the  shore  to  the  vessel,  which 

'  ia  a  difficult  and  tedious  operation. 

8ome  shipping  companies  have  specially  constructed  motor 
boats  to  facihtate  the  work  of  loading,  but  in  certain  parts  these 
ue  found  to  be  inadequate  to  meet  the  circumstaucea  of  a  shallow 
^ore  and  heavy  aurf. 

Where  vessels  are  trading  in  palm  oil,  the  boata  have  to  be  so 

istructed  to  take  a  number  of  casks  or  jnmcheona. 

G}«netally   speaking   the   surf   boats  are   divided   into   two 

ifierent   claases.     The   two-jmncheon   boat,    i.e.    one   which    is 

iged  internally  to  accommodate  two  caska  of  palm  oil,  are 

1  for  beach  work.     They  are  canted  over  on  one  aide  and  the 

s  are  simply  rolled  in.     There  are  no  side  benches,  buoyancy 

C8,  mast,  nor  sails. 

The  thTee-(iHncheon  bouts  are  arranged  to  take  throe  casks  of 

Bpalni  oil  between  the  thwarts;  they  ar^iittod  with  the  usual  side 


benches,  buovancv  tanks,  and  lilting-liooks.  These  boats  form  a 
part  of  the  vessel'a  statu- 
te iry  equipment,  and  are 
not  engaf;ed  in  beach 
>v(irl(,  but  attached  to 
ilie  veMel.  A  featnre  of 
the  equipment  of  a  8urf 
beat  is  that  they  are 
propelled  with  jxid^iles, 
not  oars. 

In  view  of  the  hazard- 
1.H1S  nature  of  the  work 
in  which  these  boats  are 
enjiaj^ed,  partirular  at- 
tention is  paid  to  the 
structure,  which  is  made 
stroni:  enou<;h  and  formed 
in  aiich  a  way  as  to 
iiinet  the  heavy  pounding 
received  from  a  shore 
8urf. 

A  ^'Cneral  idea  of  the 
aiTan;remeiit  of  midship 
section  is  obtained  by  re- 
fcroncc  to  Fig.  155'  It 
will  he  seen,  in  the  first 
|)lace.  that  the  planking 
is  much  thicker  than  the 
iiiHlinary  ship's  boat,  and 
is  worked  on  the  "carvel" 
method,  to  enable  the 
:  timbers  to  lie  completely 
home  to  their  work  and 
i^ive  the  planking;  the 
nmximum  amount  of  sup-' 
port. 

The  thickness  is  I  in., 
except  at  the  bilge,  where 
it  is  1 1  in.  The  width  of 
the  plankti  varies  from 
4!  t()  0  ill.,  with  the  gat- 
biiiird   not   exceeding  6| 

to| 


I 


These   planks 


worked   in   one    length   from 


^    >. 


SURF  BOATS 


275 


i  avoided.     The  material  is  uuiially  pitch 


Ptts  being  thui 
pical-dimensioned  boat  would  be — 
26'  0'  X  6'  10*  X  2'  lOi' 

The  whole  character  of  the  aurf  boat  is  difierent  to  the  ordinary  " 
pulling  boat,  and  the  relation  between  the  length  and  breadtji 
has  not  the  same  value  owing  to  the  particular  formation  of  the 
enda.  The  design,  therefore,  has  to  be  treated  on  its  own  merits 
in  order  to  meet  the  particular  circumstances  of  the  case.  The 
dimensions,  general  formation  of  structure,  and  other  qualities 

•    have  been  based  upon  the  experience  gained  in  actual  work. 
The  boat  is  double-bowed,  with  great  cut-up  both  forward  and 
aft.     If  reference  is  made  to  Fig.  154,  the  reader  will  find  illus- 


I 


Fio.  156. — Midship  BtotioQ  o£  surf  boat. 


trated  a  completed  surf  boat,  constructed  by  Messrs,  Philip 
Winram  and  Son,  of  Liverpool.  The  firm  has  been  good  enough 
to  allow  the  writer  full  opportunity  to  give  detail  scantlings  of 
these  particular  boats. 

Messrs.  Eider  Dempster  and  Co.,  Ltd.,  have  quite  a  number  of 
Burf  boats  carried  on  their  vessels  trading  eastward,  and  it  may 
be  remembered  that  when  the  a. a.  Falaba  was  torpedoed  by  the 
enemy,  the  surf  boats  played  no  mean  part  in  saving  a  large 
number  of  lives. 

It  will  be  seen  from  the  figure  referred  to,  that  the  stem,  keel, 
and  sterapost,  are  in  one  piece,  bent  to  shape,  from  gunwale  to 
gunwale.     The  scantlmgs  arc  2^  in.  deep  by  SJ  in.  in  breadth. 

The  thwarts  are  of  heavy  scantliug,  being  7  in.  in  width  and 
3  iiL  in  thickness.  Four  thwarts  are  fitted  in  two-puncheon 
boats,  and  five  in  three-puncheon  boats.  Tie  rods  f  in.  in 
diameter  are  worked  under  the  thwarts  from  plank  to  plank  and 
well  secured  to  the  outside,  to  assist  in  binding  the  boat  together. 


376 


SHIPS'  BOATS 


The  deadwoods  aiul  apruus  are  seciLTM]  from  material  gtoi 
to  ehapc  and  are  in  one  piece,  sided  4J  in,  and  moulded  ij  to  5  in.  J 

The  keelson  ia  bent  at  each  end  to  meet  the  deadwoods  with  J 
which  it  scarpLa,  sided  4j  in.  and  moulded  2J  in.  Timbers  are  J 
of  exceptional  sti'eDgth,  fitted  from  gtinwale  to  gunwale,  spaced  I 
from  8  to  9  in.  apart,  2J  in.  sided  and  IJ  in.  moulded. 

There  is  an  upper  stiake  of  oak  or  other  suitable  hardwood,  I 
6  in.  by  1  in.  in  thickness,  and  immediately  below  is  fitted  an! 
extra  thick  strake  of  American  rock  elm,  termed  the  bend,  which  I 
is  secured  to  every  timber  with  bolts  and  clenched  on  rings.  The  i 
scantling  is  3J  in.  by  2  in.,  and  fitted  in  one  length. 

Sister  keelsons  are  fitted  between  the  end  thwarts  which  act 
as  riders  for  the  casks.     Bilge  pieces,  risings,  and  stringers,  are 
fitted   in  one   piece  and  thoroughly   secured   to  timbers  and  J 
planking. 

The  knees  are  of  the  special  clamp  type,  as  iltustiated  i 
Fig.  86. 

Between  each  pair  of  thwarts,  cask  riders,  two  in  number,  are  1 
fitted,  made  up  of  half-rpund  iron  bars. 

Cross  chocks  are  fitted,  as  shown  in  Fig.  155,  four  in  number,  I 
on  each  side,  with  galvaikised  iron  half-round,  IJ  in.  wide,  turned  1 
over  the  gunwale  inside  and  fastened  below  through  the  chock,  ' 
with  bolts  clenched  on  rmgs. 

Iron  breaathooks  and  stem  straps  are  fitted  and  well  aecuredl 
with  bolts. 

A  stem  plate  and  skeg  band  are  fitted  fore  and  aft,  and  thaj 
usual  keel  plates,  et«.,  in  connection  with  the  lifting  arrangem 
are  the  same  as  those  approved  for  ordinary  pulling  boats. 

Good  stout  ring  bolts,  f  in,  in  diameter,  are  fitted  on  the  outsidi 
to  enable  the  boat  to  be  hauled  up  on  the  beach,  and  two  sim 
bolts  fitted  inside  for  use  with  the  painter. 

The  usual  practice  is  to  coat  the  inside  with  tar. 

The  main  consideration  throughout  the  construction  of  t 
particular  type  of  boat,  is  streng^.     The  arrangement  of  co 
binations,   etc.,  necessitate  good   workmanship,   and    seasoned 
material  is  absolutely  necessary. 

The  building  of  surf  boats  is  practically  confined  to  tiie  Livet 
pool  district. 

Sheer  is  given  greatly  beyond  the  standard  for  a  Class.  1 
lifeboat,  and  in  conjunction  with  the  amount  of  cut-up  at  t' 
stem,  allows  the  boat  to  rise  to  the  waves  or  surf,  and  keep  t 
interior  fairly  dry. 

A  typical  specification  indicating  scantlings  and  material  i 


SUKF  BOATS  277 

inserted  for  information.  There  may  be  very  slight  differences 
in  dimensions  among  the  various  boatbuilders,  but  the  following 
will  serve  to  give  a  general  idea  of  the  main  considerations. 


THREE-PUNCHEON   SURF   BOAT. 

Dimensions  :  26'  0^  x  6'  10"  x  2'  lOJ^ 

Keel. — American  rock  elm  V  x  2^^.  Turned  in  one  length 
from  stem-head  to  sternpost-head. 

Deadwoods  and  Aprons. — EngUsh  oak,  in  one  piece,  5  in.  sided, 
and  moulded  as  required. 

Timbers. — -American  rock  elm,  turned  to  shape  2J''  X  1 J"^, 
spaced  8  in.  centres. 

Planking. — Pitch  pine  or  red  pine,  1  in.  thick,  from  4|  in. 
to  5  in.  width  of  plank,  13  strake^  each  side.  Garboard  strake 
not  to  be  wider  than  6.J  in. 

Bends. — ^American  rock  elm,  3|"  X  2",  in  one  length. 

Bilge  Planks. — Pitch  pine,  3 J"  X  IJ",  in  one  length. 

Topstrake. — American  elm,  1  in.  thick,  in  one  length. 

Gunwale. — American  elm,  2|  in.  Square,  in  one  length. 

Keelson. — American  elm,  5"  X  1|",  to  run  well  up  to  the  dead- 
woods. 

Sister  Keelsons. — Pitch  pine,  3"  X  3^,  to  nin  between  the  end 
thwarts. 

Bilge  Pieces. — Pitch  pine,  3 J"  X  IJ^,  in  one  length  from 
dead  wood  to  dead  wood. 

Risings. — Pitch  pine,  V  X  V,  in  one  length. 

Stringer. — Pitch  pine,  3"  x  l^'',  in  one  length. 

Thwarts. — Pitch  pine,  7"  X  3",  and  spaced  to  receive  3 
puncheons  of  oil. 

Knees. — 2 J  in.  iron  cramp  knees,  forming  iron  rubbers  outside, 
strongly  and  thoroughly  through  fastened. 

Breasthooks. — Iron,  2  J"  X  f. 

Bottom  Boards. — Pine,  1  in.  thick,  secured  to  timbers. 

Stern-sheets. — Gratings  fitted  in  accordance  with  plan. 

Cross  Chocks. — Hardwood,  4  in  number  on  each  side,  with 
galvanised  half-round  iron,  1^  in.  wide,  turned  over  the  gimwale 
on  the  inside  and  fastened  below  through  the  chock  with  bolts 
clenched  on  rings. 

Ganghoards. — To  be  pitch  pine  of  dimensions  to  suit  the  lifting 
hooks. 

Fastenings.- -T\\Q  frame  to  be  well  bolted  with  galvanised 


278  SHIPS'  BOATS 

iron  bolts,  and  clenched  on  rings.  The  planking  to  be  fastened 
with  copper  nails  and  well  turned  down  on  the  timber,  to  the 
load-line. 

The  bends  to  be  bolted  through  every  timber  and  clenched  on 
rings. 

The  bilge  pieces  to  be  bolted  through  every  other  timber  and 
clenched  on  rings. 

The  keelson  and  sister  keelsons  to  be  well  bolted  and  clenched 
on  rings. 

Ironvxyrk,  etc, — Galvanised  iron  ringbolts,  fitted  inside  and 
outside  of  boat,  of  sufficient  strength  to  lift  boat  on  end,  and  to 
be  efficiently  fastened.  Stem,  skeg,  and  keel  plates  to  be  well 
secured  and  galvanised.  Bolts  to  be  fitted  imder  the  two 
midship  thwarts,  to  have  good  heads  and  plates  under  same. 

Lifting-hooks  to  be  fitted  in  accordance  with  approved  plan 
of  scantlings,  and  of  sufficient  strength  to  lift  boat  with  the  full 
complement  of  persons. 

Two  chafing  irons  about  2  ft.  6  in.  in  length  to  be  fitted  at 
each  side  of  boat. 

Brass  socket  and  double  plugs  secured  with  chain. 

All  iron  work  to  be  galvanised. 

The  material  used  in  the  construction  of  these  boats,  as 
also  the  workmanship  and  finish,  to  be  of  the  very  best. 

The  planking  to  be  caulked  and  puttied.  The  inside  of  the 
boat  to  receive  two  coats  of  the  best  white-lead  paint  and  three 
coats  outside. 

Six  half-round  iron  cask  riders  fitted  between  the  thwarts. 

The  inside  of  boat  is  usually  coated  with  tar,  in  lieu  of  one 
joat  of  paint,  which  is  matter  to  suit  the  requirements  of  the 
shipowner. 

SECTION  D.— STEEL  BOATS 

It  is  a  remarkable  feature  in  connection  with  the  construction 
of  lifeboats  in  the  United  States  of  America,  where  there  is  an 
abundance  of  suitable  timber,  that  the  metallic  boat  appears  to 
find  most  favour. 

Several  firms  in  Great  Britain  make  a  speciality  of  steel- 
constructed  boats,  but  the  demand  is  a  very  Umited  one  in  com- 
parison with  those  built  of  wood.  However,  the  arguments  used 
by  these  firms,  and  by  masters  of  vessels  who  have  had  experience 
with  the  metallic  lifeboat,  as  to  their  general  adoption  under 
special  circumstances,  cannot  be  disregarded. 

The  lelativo  merits  of  lifeboats  constnicted  of  steel  compared 


STEEL  BOATS 


279 


with  those  of  wood,  have  very  frequently  been  disciisged,  and  it 
is  advocated  by  those  persons  who  favour  tlie  former,  that 
wooden  Ufeboata  carried  on  vessels  passin;;  through  the  tropics, 
are  of  little  value  when  ct>nstrueted  of  woods  such  aa  larch  or 
wych  elm,  unless  the  plankint;  is  maintaini'd  in  a  constant 
condition  of  moisture,  which  is  undesirable,  Tlie  practice  of 
filling  boats  with  water  up  to  about  two  feet  below  the  gunwale 
should  be  discouraged,  for  the  action  of  the  water  on  the  planic 
fastenings  has  the  opposite  effect  to  tliat  which  would  be  imposed 
on  the  boat  when  afloat.  There  should  never  be  any  necessity  for 
this,  and  wooden  boats  should  be  constructed  of  such  material  as 
will  obviate  recourse  to  such  a  procedure.  No  objection  could  be 
raised  to  hoseing  the  outside  planking  during  the  early  morning 
before  the  heat  of  the  sun  is  great. 

With  a  steel  boat  the  variation  of  the  weather  has  little  effect,  if 
any,  and  remains  in  a  condition  for  safe  launching  at  the  moment 
required. 

There  is  no  doubt  that  where  vessels  are  constantly  trading 
on  the  seas  and  inland  waters  of  the  tropics,  steel  boats  serve 
their  purpose  admirably,  and  their  adoption  can  be  recommended. 

An  argument  for  consideration  is  that  steel  boata  can  some- 
'timea  be  launched  from  the  deck  of  a  steamer  with  a  certain 
degree  of  safety,  when  a  heavy  sea  is  running,  that  would  make 
the  operation  one  of  great  danger  to  a  wooden  boat. 

The  steel  boat  might  become  indented  if  brought  into  violent 
contact  with  the  ship's  side,  but  would  remain  in  a  condition  of 
seawortliiness ;  whereas  the  wooden  lifeboat  runs  the  risk  of 
smashing  the  gunwale  and  planking  during  the  process  of  lowering. 
There  may  not  be  much  in  this  argument,  because  if  there  are  any 
projections  on  the  side  plating  of  a  vessel,  the  skin  of  the  steel 
boat  would  probably  be  pierced,  and  a  damaged  steel  boat  is  more 
difficult  to  temporarily  repair  than  a  wooden  one. 

The  argument  of  most  value  for  the  adoption  of  the  metallic 
boat  is  in  the  case  where  the  inboard  lifeboats  are  in  close  prox- 
imity to  the  funnels.  The  influence  of  such  great  heat  on  any 
type  of  wooden  boat  in  this  position  would  have  a  damaging 
effect  on  the  planking  and  render  the  lifeboat*  unfit  for  service. 
The  writer  has  noticed  in  the  vessels  of  Messrs,  Alfred  Holt  and 
Co.,  that  invariably  the  owners  and  shipbuilders  have  considered 
this  question  in  their  arrangement  of  boat  stowage.  If  reference 
ia  made  to  Fig.  227  it  will  he  seen  that  the  outer  boat  stowed 
immediately  under  the  davits  is  constructed  of  wood,  while  the 
one  on  the  transporter,  which  has  been  moved  from  the  inboard 


280  SHIPS'  BOATS 

position  and  in  close  proximity  to  the  funnels,  is  built  of 
steel. 

In  the  case  of  fire  on  board  a  vessel,  there  would  certainly  be 
less  risk  of  damage  to  the  boats  if  they  were  constructed  of 
steel. 

The  object  of  this  treatise  is  not  to  recommend  one  particular 
type  of  boat  as  possessing  special  qualifications  for  their  general 
adoption  on  vessels,  but  to  deal  with  the  advantages  and  dis- 
advantages of  each,  and  so  enable  precautions  to  be  taken  to 
avoid  the  difficulties. 

After  a  steel  or  metallic  lifeboat  has  been  in  service  for  some 
time,  the  hull  presents  an  uneven  a'ppearance  from  the  effect  of 
coming  into  contact  with  the  ship's  side,  or  being  dumped  down 
with  undue  violence  on  the  stowage  chocks,  and  it  may  not  be 
out  of  place  to  state  that  the  crew  of  an  ordinary  cargo  steamer 
are  "  no  respecters  of  patent  lifeboats." 

The  main  complaint  raised  against  the  general  adoption  of  the 
metallic  lifeboat,  is  the  question  of  corrosion.  From  this  point 
of  view  there  is  cause  for  anxiety,  unless  there  is  a  frequent 
jieriodical  inspection  made  of  the  interior  of  the  boat  every  six 
months,  or,  at  the  very  least,  once  in  twelve  months. 

The  upkeep  and  oversight  of  all  lifeboats,  whatever  the  tjrpe 
may  be,  largely  depends  upon  the  energy  and  interest  of  the 
ship's  officers,  particularly  the  chief  officer.  If  steel  boats  are 
left  to  themselves  without  the  occasional  surveys  referred  to, 
then  the  inevitable  ro^sult  is  really  no  fault  of  the  firm  who 
constructed  the  boat,  and  cannot  be  used  as  an  argument  in 
detriment  to  the  steel  boat. 

Where  corrosion  is  likelv  to  occur  is  in  the  vicinity  of  defective 

«  ft.* 

galvanising,  or  where  the  surface  has  become  chipped  during  the 
process  of  riveting. 

The  buoyancy  air-cases  sliould  be  removed  at  each  survey, 
and  a  careful  inspection  made  for  any  signs  of  corrosion,  particu- 
larly in  way  of  the  rivets,  all  woodwork,  at  the  keel  seam,  and 
encls  of  boat,  at  the  ends  of  thwaii^s,  and  especially  behind  the 
metal  buoyancy  tanks  ;  also  in  way  of  the  welds  where  the  skin 
is  constructed  on  this  method. 

In  dealing  witli  })oats  which  have  been  in  service  for  a  consider- 
able period,  it  will  usually  be  found  that  if  any  wastage  of  material 
has  occurred,  this  is  situated  along  the  bilge,  and  particularly 
in  way  of  the  supporting  chocks.  In  this  connection  it  is  essential 
for  a  (louhliug-plate  to  be  always  riveted  to  that  portion  of  the 
shell  which  lests  on  the  chocks,  and  fuiiher  precaution  could  be 


STEEL  BOATS 


281 


taken  with  advantage  to  the  boat,  by  fitting  sheet  iron  or  canvas 
well  soaked  in  white  lead  paint,  on  the  upper  surface  of  the 
wooden  stowage  chocks. 

The  shell  plating  is  galvanised  inside  and  out,  but  there  is 
always  the  diflBculty  of  securing  a  proper  protective  coating  to 
the  heads  of  the  rivets,  although  they  are  tinned.  Yellow  metal 
or  composite  rivets  are  not  admissible,  owing  to  the  effect  of 
galvanic  action  which  would  be  created  between  the  two  metals. 
Special  precautions  have  to  be  taken  to  avoid  this  difficulty  when 
metal  buoyancy  tanks  are  fitted. 

Messrs.  Mechan  and  Sons,  Ltd.,  of  Scotstoun  Iron  Works, 
Glasgow,  have  for  many  years  specialised  in  the  ccmstruction  of 


-  FLUSH      BUTT   — 


^ 


EMBOSSSO 


^ 


-  LAPPED     BUTT  - 


Fia.  15(). 


Fio.  167. 


Fawkes'  patent  embossed  framing.     (Pat.  No.  22732-1910.) 

steel  boat«.     This  firm  also  build  the  "  Lundin  "  })ontoon  lifeboat 
referred  to  in  Section  P]  of  Part  IV. 

The  Hfeboats  of  C-lasses  Lv  and  IIL  are  constructed  of  steel 
plates  rolled  on  the  Siemen's-Martin  open-hearth  acid  process. 
The  plates  are  blocked  to  the  required  shape  and  planished  to  a 
smooth  surface.  The  frames  are  formed  on  special  lines,  known 
as  the  "  Fawkes'  patent  embossed  framing,"  which  obviates  the 
necessity  of  fitting  special  timbers.  The  method  is  illustrated 
in  Figs.  15G  and  157,  the  spacing  between  the  embossed  frames 
being  about  2  ft.  Tlie  laps,  or  ends  of  the  plates,  are  embossed 
and  connected  to  one  another  by  steel  rivets  tinned  on  the 
outside.  Fig.  150  (up{)er)  shows  the  steel  plates  joggled  so  as 
to  preserve  a  flush  surface  on  the  outside,  which  is  of  great 
advantage  to  a  motor  boat.  Fig.  156  (lower)  shows  the  skin 
plating  worked  with  an  ordinary  lap.  In  both  cases  the  interior 
of  the  embossexl  frames  are  well  coated  with  protective  paint 
and  filled  with  plastic  cement. 


282  SHIPS'  BOATS 

The  steel  plates  are  blocked  to  the  correct  shape,  embossed 
in  a  special  rolling  machine,  all  the  work  completed  except  the 
actual  riveting,  and  then  galvanised  in  the  firm's  own  baths  by 
the  special  hot  process.  The  plates  are  then  erected  and  the  hull 
is  double  riveted  with  tinned  steel  rivets. 

The  sp^ms  of  the  Ught  plated  hulls  are  made  watertight  by 
inserting  special  tape  dipped  in  red  lead,  but  the  heavier  hulls  are 
caulked. 

Boats  which  are  constnicted  in  sections  on  the  principle 
referred  t^)  are  very  suitable  for  transporting  abroad  for  use  on 
inland  waters. 

In  a  double-bowed  boat,  the  stem,  stempost,  and  keel  are  in 
one  length,  bont  to  shape,  and  consist  of  a  rolled  bar  of  section 
shown  in  Fig.  157,  the  shell  plating  being  single  riveted  to  this  bar. 


e^forcft 


ar££L 


/f£  iff^e 


SECTION  ELEVATION 

Fi(3.  158. — Method  of  securing  crutches  and  li{e-lino^«*. 

The  thwarts,  side  seats,  etc.,  are  usually  formed  of  teak  or 
yellow  pine,  of  scantlings  equal  to  wooden  lifeboats.  It  is 
essential  to  keep  all  woodwork  in  a  metallic  boat  from  having 
direct  contact  with  the  hull,  but  where  the  gunwale,  upper  strake, 
and  rubber  are  of  wood,  direct  attachment  to  the  steel  hull  cannot 
be  avoided.  In  some  boats,  Mechan's  patent  embossed  steel 
gunwale  is  adopted,  which  is  a  combination  of  gunwale,  upper 
strake,  and  rubber.  Fig.  161  illustrates  the  arrangement  in 
section.  An  alternative  scheme  for  fitting  a  steel  gunwale 
which  consists  of  a  bulb  angle,  is  shown  in  Fig.  158. 

The  thwart  knees  and  breasthooks  are  made  of  steel  on  the 
ombossod  principle,  riveted  to  the  liull  plating  and  bolted  to  the 
thwarts.     (See  Fig.  159.) 

Life-line  rings  are  secured  to  tlie  hull  just  below  the  rubber  or 
bulb  of  tlie  gunwale  by  rivet/ed  cleats,  spaced  18  in.  apart  as 
shown  in  Yvx.  158. 


STEEL  BOATS  283 

Watertight  air-cases  are  fitted  in  steel  boats,  but  an  addition 


SECTION  ELEVATION 

Fio.  159. — Method  of  secnrjng  thwnrts  to  aides. 


li 


fT 


E5 


SHeil.  ^LKTMt 


ELEVATION  SECTION 

FlO.  160.— Details  of  lifting-hook  for  stwl  lifeboat. 


is  made  to  the  cubic  capacity  so  as  to  give  the  steelboat  buoyancy 
equal  to  that  of  a  wooden  boat. 


284  SHIPS'  BOATS 

The  method  of  obtaining  the  correct  volume  of  metal  air-cases 
is  dealt  with  in  Section  C,  Part  VI. 

Particular  care  should  be  given  to  the  arrangements  made  for 
the  removal  of  the  air-cases  to  faciUtate  easy  access  when  the 
periodical  inspections  are  made  to  ascertain  the  condition  of 
the  hull. 

The  tanks  must  be  kept  from  contact  with  the  steel  shell, 
a  simple  arrangement  being  the  fitting  of  two  lengths  of  rope 
round  the  tanks  to  act  as  a  fender. 

The  lifting-hooks  are  formed  at  the  head  in  similar  fashion 
to  those  approved  for  wooden  lifeboats,  and  the  scantlings  are 
identically  the  same,  as  there  is  very  little  difference  in  the  weights 
of  the  steel  boats  as  compared  with  those  of  wood.  There  is  a 
difference  to  the  keel  plate  fittings,  owing  to  the  formation  of 
the  keel.  The  method  of  securing  the  lifting-hook  to  the  hull 
is  shown  in  Fig.  160. 

The  whole  of  the  inside  and  outside  of  the  boat  is  coated  with 
two  good  coats  of  oil-paint. 

TYPICAL   SPECIFICATION    FOR    GALVANISED   STEEL 

LIFEBOAT. 

Dimensions  :  28'  O''  X  8'  6''  X  3'  6''  =  50  persons. 

Shell  Plating. — Siemens-Martin  mild  steel  sheets,  14  B.W.G., 
built  on  Fawkes'  patent  embossed  steel  framing  principle,  flush 
plated  and  flush  riveted  on  outside.  Doubling  plates  in  way  of 
chocks.     Frames  filled  with  plastic  bitumastic  composition. 

Galvanimig . — All  steel  plates  galvanised  by  the  hot  process 
after  working  to  shape  and  punched. 

•    Keel,   Stem,   and  PosL—Oi    bulb  tee,   5''  X  1 1''  X  IT  X  T- 
Section  of  specially  rolled  steel  bar. 

Gunwale. — Of  specially  rolled  bulb  angle  section. 

Thwarts.— Oi  pitch  pine,  8x12''. 

Side  Be^iches. — Of  pitch  pine,  1  in.  thick,  continuous  over 
thwarts. 

Rudder  and  Tiller. — Rudder  of  English  elm  and  tiller  of  ash 
or  elm. 

Buoyancy  Tanks. — C'Onstructed  of  yellow  metal  of  21  ozs. 
per  sq.  ft.  To  be  securely  held  in  place.  Rope  strops  wound 
roimd  tanks  to  prevent  injury  by  contact  with  shell. 

Mou7i(i7ujs. — Galvanised  steel  thwarts  supports,  embossed 
kneas,  mast  step,  mast  hasp,  cleats,  1|  set  galvanised  steel 
rowlocks,  double  banked  at  all  thwarts,  and  steering  rowlock 


STEEL  BOATS 

tltteii,  all  attacheiL  with  galvanised  chain.  Galvanised  shackles 
at  ends. 

Lifting-Hooks. — ^To  be  fitted  as  per  special  plan. 

Gear  Box. — Pine  box  for  stowing  details  of  outfit  supplied 
and  fitted. 

The  Seamless  Steel  Boat  Co,,  Ltd.,  of  Wakefield,  13  another 
well-known  firm  who  have  specialised  in  a  particular  type  of 
construction,  both  for  ships'  boats  and  motor  boats.  They  have 
their  own  patent  method  of  formin>;  the  ahoU  plating. 

The  hull  is  made  of  sheets  of  Siemens-Martin  mild  steel, 
pressed  into  the  requii-ed  shape,  welded  together  at  the  butts, 
and  riveted  to  a  steel  keel  bar  of  the  bulb  section,  which  fonns  the 
stem,  keel,  and  sterapost.  The  whole  of  the  shell  plating  and  steel 
work  attached,  is  thoroughly  galvanised. 

The  inside  of  the  hull  is  covered  with  two  coats  of  bitumastic 
solution,  and  the  outside  with  two  coats  of  the  best  white-lead 
paint. 

The  top  atrake  is  of  teak,  gunwale  of  j^ierican  elm  (or  formed 
of  special  moulded  steel),  rubbers  uf  American  elm,  thwarts,  side 
aeate,  and  deck  ends,  of  yellow  or  red  pine. 

Canvas  soaked  with  white  lead  paint  is  fitted  between  the 
plating  and  keel,  stem,  and  stempoat. 

Wood  timbers  arc  sometimes  fitted,  and  sprung  into  position 
from  keel  to  gimwale,  secured  in  such  a  way  that  they  can  be 
removed  for  painting. 

A  plan  which  has  found  favour  with  the  firm  is  to  fit  a  lijjht 
steel  angle,  riveted  to  the  bar  keel,  and  guuwale,  so  as  to  be 
easily  removed,  with  a  piece  of  elm  fixed  to  the  bosom  of  the  bar 
to  hold  the  tanks  off  the  sharp  edge  of  the  bar.  The  idea  of  the 
angle  is  not  to  atiilen  the  boat,  but  merely  to  hold  the  tanks  away 
from  the  hull. 

Mr.  James  ,\nder8on,  in  a  paper  read  before  the  Listitute  of 
Engineers  and  Shipbuilders  in  Scotland,  on  the  23rd  of  November, 
1915,  referred  to  a  new  method  of  forming  steel  plates  for  the 
construction  of  steel  boats,  a  system  which  has  already  been  in 
operation  in  some  of  the  American  yards.  The  boat  appears  to 
be  constructed  of  a  number  of  longitudinal  strakes  of  steel 
plating,  sliaped  in  similar  form  to  the  planks  of  an  ordinary 
chnket-built  wooden  boat,  but  the  landing  edges  are  secured 
together  by  means  of  a  double^hook  joint,  aa  shown  in  Fig.  162, 
The  joints  are  closed  and  made  watertight  with  hammers  or 
roUeis. 


286 


SHIPS'  BOATS 


The  plating  is  attached  to  a  V-shaped  steel  stem,  stempost, 
and  keel.  Wood  timbers  are  attached  to  the  shell  by  means  of 
small  lugs,  which  are  closed  in  with  the  shell  plating.  These 
lugs  have  two  sides  in  which  the  timbers  lie,  and  are  secured 
with  through  fastenings  placed  in  a  fore-and-aft  direction.  Bj 
this  method  it  is  advocated  that  no  fastenings  in  the  hull  will  be 
subjected  to  corrosion. 

An  inside  and  outside  gunwale  is  secured  to  the  plating  and 
timbers. 

The  interior  of  the  boat  is  thickly  coated  with  bitumastic 
solution. 

The  Uriited  States  Board  of  Supervising  Inspectors  have 


STffAHC 


B£'IT 


SH£ll 


DOUBLE  HOOK 
^     JOtNT 


CAfSOSSeO 


Fig.  161. — Mochan's  patent  embossed        Fig.  162. — Hooked  joints  for 
steel    gunwale.      (Pat.   No.   8852-  steel  shell   plates   of   lifo- 

1911.)  boat. 


issued  standard  regulations  governing  the  construction  of  all 
metallic  lifeboats  for  ocean-going  steamers. 

The  keels,  stems,  stemposts,  gimwales,  and  nosings,  may  be 
of  clear  grain,  sound  oak,  or  other  suitable  wood,  each  in  one 
length,  except  that  the  gunwale  and  nosings  may  be  made  in  two 
lengths.  When  made  lq  two  lengths,  the  gunwales  must  be 
scarphed  with  a  good  long  bevel  scarph,  stiffened  on  the  underside 
by  a  piece  of  gimwale  material,  at  least  2  ft.  in  length,  \\  in.  thick, 
and  the  width  of  the  gunwale. 

The  stem  to  be  of  natural  or  steamed  crook,  scarphed  at  least 
9  in.  in  length  on  the  keel,  and  fastened  thereto  with  two  f  in. 
through  clinch  bolts  driven  through  the  deadwood. 


STEEL    BOATS 


287      ^1 


The  sternpost  to  be  stepped  over  the  end  of  the  keel,  lialf 
the  length  of  the  stempost,  and  recessed  at  least  2J  in.  deep  into 
the  keel,  the  whole  to  be  secured  on  the  inside  by  a  crook  or  knee 
of  sufficient  width  to  receive  the  flanges  of  the  shell  plates. 

Each  joint  of  the  stem  and  stempost  ia  fitted  with  two  |  in. 
atop  waters,  under  the  shell  flanges.  Bearding  of  stem  and 
stempost  is  not  to  be  leas  than  1|  in. 

The  flanges  of  the  shell  plates  on  boats  not  over  20  ft.  in  length, 
to  lap  on  the  keel,  stem,  and  stempost,  at  least  2}  in. ;  in  boats 
over  20  ft.,  and  not  over  24  ft.  in  length,  at  least  2^  in. ;  and  in 
boats  over  24  ft.  long,  at  least  2J  in.,  to  be  fairly  drawn  up  and 
nailed  over  a  strip  of  No.  6  cotton  duck,  the  width  of  the  flange, 
and  secured  by  three  rows  of  galvanised  naila  driven  zigzag 
fashion. 

No  part  of  the  keel,  stem,  or  stempost,  outside  of  the  shell 
flanges  to  be  covered  with  sheet  steel. 

The  following  particulars  give  the  approved  limiting  gauge 
of  shell  plates,  viz. : — 

Length  of  boat.  Gauge 

Up  to  and  including  20  ft 18  B.W.G. 

Over  20  ft.  and  not  over  24  ft 16  B.W.G. 

Over  24  ft 14  B.W.G. 

All  the  .seams  and  Joints  ate  double  rivet«d.  The  aeains 
and  butt  laps  are  not  less  than  Ij  in.  The  centre  of  the 
*■  of  rivets  nearest  the  .edge  of  a  ^eet  are  about  |  in.  from 
the  edge.  Rivets  are  staggered  with  not  less  than  18  rivets  to 
the  foot,  having  countersunk  heads.  The  diameter  of  shank  of 
rivet  is  not  less  than  No,  10  B.W.G. 

The  width  or  siding  of  wood  keels,  stems,  and  stemposts,  vary 
from  1-8  in.  for  an  18-ft,  boat  to  2'8  in.  for  a  28-ft.  boat,  while  the 
depth  or  moulding  variea  from  4'2  to  50  in.  respectively. 

Steel  having  one-sixth  of  the  approved  sectional  area  of  wood, 
may  be  used  in  lieu  of  wood  fur  keels,  stems,  stemposts,  and 
gunwales,  of  metallic  lifeboats, 

The  keels  of  all  boats  over  26  ft.  in  length  are  strengthened 
by  the  addition  of  a  main  keelson  extending  not  more  than  two- 
thiids  the  length  of  the  boat,  and  having  one-half  the  area  of  the 
main  keel,  to  which  it  is  through  fastened  wtth  |  in.  clinch  bolts 
spaced  not  less  than  14  in. 

The  sizes  of  wood  gunwales  vary  from  Ij  in.  in  depth  by[2  in. 
in  width  for  an  18-ft.  boat  to  2|  in.  by  2|  in.  for  a  30-ft,  boat. 


L 


288  SHIPS'  BOATS 

TJie  giinwalea  are  attaclied  to  the  thwarts  by  steel  braces  and 
teed  to  the  thwarte,  and  secured  thereto,  and  also  to  the  steel 
plating  by  bolts,  the  aecuring  bolta  to  plating  being  clinched  on 
the  outside. 

The  sheer  strake  is  brought  to  within  a  J  in.  of  the  top  of  the 
gunwale,  nailed  thereto  by  IJ  in.  boat  nails,  spaced  6  in,  apart. 

Thwarts  are  made  of  clear  yellow  pine  or  fir,  and  are  of  the 
following  scantLn^s,  nz  : — 

Length  i>[  bust,  Souitling. 

20  ft.  and  under 7i'  X  IJ'  ' 

21  ft.  to  24  ft 8'  X  li' 

Over  24  ft 9'  X  li 

All  thwarts  over  Ij  ft.  lon^  are  supported  by  stanchions  of 
pine  1  in.  by  5  in.  Every  thwart  is  aecuri3d  at  each  end  to  the 
boat  side  bv  a  double  or  u  flange  of  No,  Iti  plate,  riveted  to  the 
shell  with  five  rivets,  the  thwarts  being  fitted  between  the  flanges 
and  secured  thereto  by  five  boat  nails  driven  down  through  the 
upper  flanges,  tliwarte,  and  lower  flanges,  and  turned  over 
beneath. 

Midship  footings  are  fitted  to  the  inside  of  the  bull  over  a  coat 
of  lead  paint,  and  held  in  place  by  straps  of  No.  18  plate  1^  in. 
wide.  The  midship  footings  in  boats  over  18  ft.  and  not  over 
24  ft.  long,  are  not  less  than  1  in.  thick  by  12  in,  wide,  and  have 
three  footings  on  each  side,  1  in.  thick  by  7,  6,  and  4  in.  respec- 
tively in  width.  Boats  over  26  ft.  in  length,  ha\Hrig  a  keelson, 
are  fitted  with  three  footings  on  each  side,  1  in.  thick  by  8  in.,  6  in., 
and  5  in.  respectively  in  width.  The  securing  straps  pass  up 
through  an  aperture  in  the  middle  of  each  footing  and  receive  a 
toggle  of  gas  pipe,  f  in,  in  diameter,  and  of  a  length  not  less  than 
two-thirds  of  the  width  of  the  footing.  The  number  of  toggles 
fitted  in  each  footing  varies  from  four  to  six. 

Breasthooks  are  formed  of  steel,  varying  in  size  from  i  in. 
thick  by  IJ  in.  in  width,  to  f\  in.  by  1  j  in.  No  breasthooks  are 
leas  than  9  in.  long,  and  are  fastened  through  the  gmiwale  on  each 
side,  with  three  {  in.  button-headed  bolta  clinched  over  the  shell 
plating. 

Rudders  are  made  of  clean,  straight^grained  oak,  or  fir,  stiffened 
across  the  bottom  edge  by  a  piece  of  wood  of  the  same  character, 
properly  nailed. 

Each  hfeboat  is  fitted  with  an  automatic  plug.     (See  Fig.  112.) 


PART  VI 

SECTION     A.— DETAILS    OF    LIFTING    HOOKS,    KEEL 

PLATES,  CHAIN  SLINGS,  ETC. 

Lifting  Hooks. — The  fitting  of  suitable  lifting  hooks  in  a 
lifeboat  is  of  the  greatest  importance.  Provision  is  made  to 
meet  the  ordinary  conditions  of  lowering  a  boat  over  the  side  of  a 
vessel  into  the  water,  with  a  disciplined  crew,  and,  in  addition, 
the  "  unusual "  or  "  extraordinary  "  circumstance  has  to  be 
well  considered.  The  passengers  may  be  in  a  condition  of 
nervous  excitement  or  panic  during  the  operation  of  lowering, 
with  a  heavy  sea  running,  and  the  work  of  launching  the  boat 
may  be  undertaken  with  the  help  of  untrained  persons.  In  such 
circumstances,  stresses  may  be  exerted  on  the  Ufting  hooks  which 
under  ordinary  conditions  would  not  be  anticipated. 

Therefore,  in  the  first  place,  the  lifting  hooks  and  their  attach- 
ments must  be  designed  so  as  to  be  strong  enough  to  carry  the 
weight  of  the  boat,  full  equipment,  the  total  number  of  persona 
appropriated  to  the  boat,  and  having  in  reserve  a,  factor  of  safety. 
This  factor  of  safety  is  the  only  feature  which  is  open  to  argument 
or  criticism,  as  its  magnitude  is  intended  to  cover  all  requirements 
and  the  ^*  unusual  '  circumstance. 

Little  attention  at  one  time  was  paid  to  this  important  question 
when  fitting  out  lifeboats  intended  for  cargo  vessels,  and  until 
within  a  matter  of  three  or  four  years  ago  it  was  quite  the  common 
practice  to  insert  welded  lifting  hooks  having  shanks  which  were 
driven  through  the  keelson  and  keel,  and  simply  clenched  over  a 
small  plate  about  J  in.  in  thickness.  The  weight  of  some  three  or 
four  tons  was  therefore  hanging  in  mid-air,  which  depended  entirely 
on  the  efficiency  of  a  very  doubtful  clench.  To  say  that  the  same 
principle  was  commonly  carried  out  in  the  case  of  lifeboats  for 
pas.seni!;er  vessels  would  be  an  exaggerated  statement,  but, 
iievorthelo.ss,  the  (juality  of  the  lifting  hook  connections  ^as  often 
open  to  .serious  doubt. 

Recent  regulations  issued  by  the  Board  of  Trade,  it  is  hoped; 

u 


290  SHIPS'  BOATS 

will  prevent  the  difficulties,  to  which  reference  has  been  made, 
occuning  in  the  future. 

"  Safety  first "  is  a  warning  which  has  riveted  itself  on  the 
minds  of  many  people  in  Great  Britian,  through  their  intimate 
contact  with  the  posters  displayed  on  the  municipal  cars,  and 
it  is  one  that  is  well  advertised  throughout  the  United  States 
of  America,  and  should  be  made  applicable  to  all  the  various 
considerations  associated  with  the  life-saving  appliances  on  board 
a  merchant  vessel. 

The  present-day  type  of  lifting  hook  may  look  heavy  in 
appearance  as  compared  with  hooks  used  for  other  purposes 
in  the  shipyard,  and  particularly  with  those  fitted  in  lifeboats 
previous  to  the  issue  of  definite  regulations,  but  in  dealing  with 
ships'  lifeboats,  there  should  be  no  doubt  on  the  question  of 
strength,  and  every  opportunity  taken  to  avoid  error  or  the 
slightest  appearance  of  weakness,  especially  when  discussing 
the  suitabiUty  of  lifting  hooks. 

Before  further  investigation,  the  instructions  issued  by  the 
Board  of  Trade  in  July,  1916,  should  be  considered.  Recent 
experience  has  added  much  to  these  requirements,  but  they  still 
form  the  basis  of  the  regulations,  and  are  as  follows  : — 

"  All  sUng  hooks  fitted  in  open  boats  should  be  of  the^erf  type, 
unless,  on  the  special  application  of  the  owners,  some  other 
approved  type  of  hook  is  adopted.  All  hooks  must  be  of  ample 
strength  having  regard  to  the  load  carried,  and  should  be  of 
wrought  iron  or  steel.     Welded  hooks  should  be  of  wrought  iron. 

"  The  proportions  of  all  parts  taking  the  weight  of  the  boat 
should  be  such  as  to  provide  a  factor  of  safety  not  less  than  four, 
and  the  arrangement  should  be  strong  enough  to  carry  the  boat, 
equipment,  and  full  load  of  persons  with  that  factor. 

"  Unless  the  bolt  and  fittings  are  tested  as  described  below, 
the  material  is  to  be  assumed  to  have  an  ultimate  strength  in 
tension  not  exceeding  18  tons  per  square  inch. 

"  If  a  higher  tensile  strength  is  claimed  for  the  material, 
or  if  the  surveyor  is  not  satisfied  that  the  strength  is  sufficient, 
the  lifting  hook,  together  with  the  sling  bolt  and  fittings  for 
attachment  to  the  boat,  is  to  be  subjected  to  a  proof  test  of  at 
least  the  total  weight  of  boat,  equipment  and  persons.  (Modified 
by  recent  instnictions,  see  Scantlings  of  Lifting  Hooks.)  A 
sample  should  also  be  tested  to  destruction  to  determine  the 
approximate  factor  of  safety. 

''  In  welded  parts,  tlie  calculated  tensile  stress  is  not  to  exceed 
three  tons  per  s(|uare  inch  with  the  dead  working  load. 


LIFTINa  HOOKS,  ETH. 


291 


"  Slinjr  honks  depending  for  their  security  upon  a  cleuflut! 
head  alone,  are  not  to  be  passed  in  new  boats  in  future.  In  all 
lifeboats  exceeding. 24  ft,  in  length,  the  sling  hooks  should  be 
secured  to  eye-plates  or  to  clamps  of  wrought  iron  or  steel  iitt«d 
on  the  top  of  the  keelaon,  and  fastened  to  it  by  iron  or  steel  screw 
boltw  nutted  on  the  inside  of  the  boat,  and  the  holts  upset.  The 
heads  of  the  bolts  should  be  ffirged  with  ample  bearing  surfaces, 
and  should  bear  on  a  substantial  plate  fit.ti?d  on,  but  not  let  into, 
the  underside  of  the  keel. 

"  Any  other  method  equally  8atisfacti>rj'  may,  however,  be 
adopted.  WTien  the  lifting  huoks  are  required  to  be  so  near  the 
ends  of  the  boat  that  they  cannot  be  directly  connected  to  the 
keelson  and  keel,  special  etreugthening  arrangements  should  be 
fitted  to  prevent  the  boat  being  strained  when  it  is  lifted.  Means 
should  be  provided  for  preventing  the  hook  bolts  from  turning." 

Before  we  can  succeasfully  determine  the  correct  sizes  of 
lifting  hooks,  to  enable  them  to  withstand  the  effect  of  a  certain 
definite  dead  load,  it  is  essential  that  sufficient  and  accurate 
data  should  be  at  our  disposal  upon  which  to  base  the  scantlings, 
We  need  to  go  beyond  the  investigations  of  theoretical  calculatiorLa 
and  secure  this  data  from  the  results  of  actual  tests. 

At  the  request  of  the  writer,  Messrs.  Scott's  Shipbuilding  and 
Engineering  Co.,  Ltd.,  Greenock,  very  kindly  carried  out  a  scries 
of  extended  testa  on  various  sizes  of  lifting  hooka,  connecte<l  to 
different;  types  of  keel  plates.  The  firm  went  to  a  great  deal  of 
trouble  to  secure  sufficient  information  upon  which  to  base  a 
full  scheme  of  scantlings  for  sizes  of  lifting  hooks  that  would  be 
strong  enough  for  the  purpose  required. 

The  boats  were  classified  into  lengths  ranging  from  15  to  30  ft. 
With  each  length  were  associated  dimensions  considered  to  be 
of  maximum  proportions.  Upon  these  dimensions  the  maximum 
dead  load  coming  upon  the  lifting  hooks  was  obtained,  which 
included  the  weight  of  the  boat,  equipment  and  full  complement 
of  persons.  As  an  example,  take  an  open  lifeboat  of  Class  I.  of 
the  following  dimensions,  which  is  not  to  standard  size,  but 
considered  as  extreme  or  of  limiting  proportions,  viz.  :  length 
26  ft.,  breadth  85  ft.,  and  depth  3-5  ft.  The  total  load  carried  by 
the  lifting  hooks  would  be  5'4  tons  ;  each  hook  would  therefore 
have  to  siistain  2-7  tons  under  working  conditions.  In  other 
words,  certain  maxJniuin  loads  were  allotted  to  each  particular 
length  of  boat,  and  the  sizes  of  the  books  were  appropriated  in 
accordance  with  these  loads. 

From  the  results  of  these  tests  the  sizes  of  lifting  hooks  and 


292  SHIPS'  BOATS 

keel  plates,  given  in  Table  XIX.,  were  based.    The  factor  of 
safety  was  three  on  the  elastic  limit. 

With  riveted  joints  and  other  combinations  it  is  somewhat 
difficult  to  obtain  the  elastic  limit  during  the  process  of  testing, 
and  it  is  usual  for  the  factor  of  safety  to  be  based  on  the  ultimate 
breaking  strength,  which  is  known  as  the  nominal  factor  of  safety. 

XT      .     1  TT,  r  n  e  ,        Breaking  Stress 

Nommal  Factor  of  Safety  =  ^^^ — ,  .      o,  — 

-^      Working  Stress 

When  we  come  to  solid  drawn  lifting  hooks  made  from  cable 
iron,  where  the  difficulty  of  obtaining  the  elastic  limit  is  not  so 
greats  it  is  very  evident  that  immediately  this  point  is  passed, 
alteration  to  form  and  permanent  set  take  place.  If  the  load 
which  produced  permanent  set,  or  the  stress  which  came  upon 
the  material  at  the  elastic  limit,  was  not  increased,  but  allowed  to 
continue  for  a  sufficient  length  of  time,  the  hook  would  eventually 
straighten  out  so  that  the  actual  strength  of  the  bolt  is  the  elastic 
limit  or  yield  point,  and  the  ratio  between  this  and  a  working 
stress  is  termed  the  true  factor  of  safety. 

m       T7    X       £  C3  £  J.        Stress  at  elastic  limit 
True  Factor  of  Safety  =  — ..^    ,  . 

Working  Stress 

From  the  point  of  view  of  obtaining  data  for  the  purpose  of 
formulating  a  scale  of  sizes  for  lifting  hooks,  testing  material  to 
destruction  after  once  the  elastic  limit  has  been  reached  does  not 
provide  us  with  much  useful  information,  beyond  giving  us  the 
additional  load  which  is  required  to  break  the  hook,  or  produce 
fracture  within  a  reasonable  length  of  time. 

The  difEerence  between  the  stress  which  discovers  the  elastic 
limit  and  that  which  produces  fracture,  is  the  reserve  strength 
of  the  hook  beyond  the  elastic  limit. 

No  useful  purpose  will  be  served  by  the  insertion  of  any  details 
of  the  tests  referred  to,  these  were  very  carefully  carried  out  with 
small  increasing  loads  to  ascertain  the  elastic  limit  of  each  indi- 
vidual hook,  and  the  deflections  were  measured  and  tabulated. 

Considerable  amount  of  work  is  put  on  the  largest  type  of 
hooks  in  forming  them  into  the  required  shape,  the  effect  of  which 
was  made  evident  at  the  test.  The  material  at  "  A,"  Fig.  163, 
immediatolv  in  way  of  the  critical  section,  was  under  a  very  acute 
stress  duo  to  the  bending  moment,  and  consequently  became 
fat  i.i«[ued.  When  a  certain  load  was  reached  it  produced  a  fracture 
to  a  depth  of  about  half  an  inch,  the  load  was  increased,  and  after 
the  hook  was  fully  broken  the  fatigued  portion  at  '*  A  "  was  found 


LIFTING   HOOKS,   ETC. 


293 


FiQ.  163 


FiQ.  104. 


FiQ.  105 


COMPARATIVE 
SECTION 


-ELEVATION  — 


Sfcr/o/^CD' 


S£CrfOf¥£.r 


FlQ.  IGtt. 


Fio.  107. 


294  SHIPS'  BOATS 

to  be  fTv.stalli.sed,  but  beyond  this  depth  the  material  showed 
gfKKl  fibre.  The  load  whicli  produced  the  initial  fracture  exceeded 
the  elastic  limit. 

The  full  thickness  of  the  material  in  lifting  hooks  of  standard 
circular  section,  is  maintained  from  the  upper  part  of  the  shank 
in  way  of  the  ganc;board  to  just  beyond  the  critical  section  ;  from 
this  position  to  the  point  of  the  hook  the  material  gradually 
tapers  to  facilitate  easy  insertion  for  the  link  on  the  block 
attached  to  the  davit  falb. 

Particular  attention  should  be  paid  to  the  distance  between  the 
point  of  the  hook  and  the  gangboard.  WTien  ordering  the  lifting 
hooks  from  the  smith  it  is  necessary  to  give  him  the  distance 
between  the  centre  of  pin  in  the  keel  plat€  to  the  top  of  the 
gangboard. 

The  particulars  of  iron  lifting  hooks  in  Table  XIX.  have  been 
standardised  tf>  obviate  the  necessity  of  carrying  out  tensile 
tests  in  every  case.  The  material  is  best  cable  iron.  Periodical 
tests  should  be  made  from  samples  of  the  material  used.  Each 
hook  is  drawn  out  of  the  solid. 

A  reduction  is  made  in  the  scantlings  when  hooks  are  made  of 
mild  steel,  but  they  are  subjected  to  a  proof  test  equal  to  one  arid  a 
quarter  times  the  total  weight  of  boat,  including  the  equipment 
and  the  full  complement  of  persons.  Each  hook  must  be 
stamped  with  the  test  load. 

No  part  of  any  lifting  hook,  whether  of  iron  or  steel,  should 
be  welded  unless  approval  has  been  obtained  from  the  Board  of 
Trade,  and  approval  is  only  given  when  each  hook  is  subjected  to 
a  proof  test  with  an  increase  in  the  factor  of  safety. 

The  writer  is  fully  aware  of  the  expression  of  opinion  among 
boatbuilders  and  shipbuilders  as  to  the  size  of  lifting  hooks, 
which  is  considered  excessive,  but  from  the  results  of  repeated 
tests,  no  reduction  in  the  scantlings  can  reasonably  be  made 
unlass  the  factor  of  safety  is  lowered. 

All  lifting  hooks  must  be  carefully  annealed  after  forging,  to 
correct  the  difficulty  already  referred  to,  which  is  produced  by  the 
amount  of  work  put  on  the  head  of  the  hook  while  being  forged. 

A  common  practice  was  to  forge  the  actual  hook  separately, 
and  weld  it  to  a  tapered  shank  as  shown  in  Fig.  1G4. 

Another  method  was  to  weld  the  hook  at  the  critical  section, 
as  shown  in  Fi^r.  IGo,  and  usually  with  another  weld  in  the  shank. 
The  lu^ad  was  loft  flat  to  facilitate  driving  the  bolt  through  the 
k(M»l  and  kc^elson.  Each  of  the  methods  referred  to  depend  on 
the  onicioncy  of  a  weld,  and  thus,  particularly  when  95  per  cent,  of 


LIFTING  HOOKS,  ETC. 


295 


mfTAstosctfew 

BOLT 


PLAN  af^O£CMPlArC  mf^-Af  M£ei  SHS^ 


or  TY^es  Saho  Cap€  tntrm? 


Fia.  108.— Method  of  securing  lifting  hook  at  gangboard,  and  method  of  fitting  keel  plate 

when  boat  is  lifted  from  the  ends. 


SHIPS'  BOATS 


TABLE 

Scaij:  op  Sizf^  fob  Liftihg  Hookb  asd  Ebei. 

To  be  trad  in  conjunction  tcilh  Fig.  168  (liftinQ 


Length  □(  boat  in  feet 


S0&.29. 


26  A  27. 


2C&25. 


Maximum    dimenBionfl    and    dead  i   amv    m     .n    ' .,    _  .. .. 

h^.    i,„-U.lir,g...ight  of  boat.      ™*J.5t„«  28-0' x?;0'x 8-75.   20-O'x8-5- 

no.  of  KfsSDS a„d *quipinenl     .  [         T 9  tons.  GB  tons.  5-4  to, 

Ttpb  of  beel  connection  . 

Material 


Thickness  of  kod  plate 
Size  of  Rocuring  pin  .  . 
No.  ol  securing  bolt';  . 
Size  of  securing  l.olts.     . 


Tj|,»A.- 

Type  "A.' 

Tspe"A." 

Iron.   1  Steel 

Iron.      Steel.       Iron.    |  Steel. 

!J"     i     HI" 

»!•■       Ill 

•     j      i;~ 

m" 

2" 

,.. 

Ij"          1} 

•     j      li" 

15" 

,j.     1      1... 

li-          If 

■|ir      1." 

3,„           ,,„ 

2J"           2J 

-    1    2!"    1    »i" 

2"            2" 

ir     1! 

-  ,  li-  1  ,,.. 

or  1   or 

0"     ■       G 

•     1     5)-          sj- 

10"     i      10" 

9i-          «. 

'     j       8-1        9" 

11"           !■" 

IS"    .    1! 

•   f   11-   ,   u- 

31"          SI 

■     1        3-     ,       3- 

li"  1  11- 

S"    1     < 

3"  ;    r 

11" 

li" 

V 

3 

3 

3 

{         It 

i:: 

3  (if  f 

2(« 

I-- 

Mi/c— Lifting  hooks  to  be  of  best  cable  it 


LIFTING   HOOKS,  ETC 


297 


XIX 

Plates  fob  Open  Boats  op  Classes  I.  and  III. 
hooks)  Fi^s.  1G8,  1G9  arul  170  {heelplates). 


24  & 

28. 

>x30'. 
ns. 

22  &  21. 

220'x7-2.Vx2-75'. 
30  tons. 

Typo  "  B." 

20A 

200'  X  G' 
2-4  t 

Type 
Iron. 

;  19. 

18  &  17. 

1 

IGiS 

IGO'xS' 
1-6  t 

Type 
Iron. 

:15. 

240'x7-i 
3-9  to 

r5'  X  2G'. 
ons. 

180'xG-26'x2-6'. 
i          1*9  tons. 

Type  "  C." 

Iron.    1    Steel. 

1 

75'  X  2-8'. 

ODS. 

Type  " 

1 

B." 

Steel. 

Steel. 

"  C." 

Iron. 

Iron. 

ij" 

111" 

Stocl. 

steel. 

1 

10" 

Vi" 

12" 
11" 

ir 

lA" 

1   5i" 

1 

li" 

li" 
ij" 

ir 

12" 

n" 

ir 

1 

li"  i 

1  "J  " 

■^16 

li" 

H" 

li" 

2" 
1>" 

H" 

ir 

1  »  " 

1" 

2J" 

lA" 

ir 

ir." 

If 

ir' 

If 

IS" 

15" 

!■'" 

1.1" 

li" 

IJ" 

li" 

ij" 

4J" 

li" 

IJ" 

,  ^r 

"^i" 

^ 

■«•;" 

1" 

4^" 

4}" 

41" 

41" 

4i" 

8}/' 

H.V'      ' 

1 

8" 

,71" 

7r' 

7" 

7" 

G>" 

6.J" 

H" 

i 

1" 

r' 

I" 

H 

1 

S'i" 

4 

i" 

r 

r 

:>'■ 
1 

— 

\ 

— 

1 
1 

—     '                   1 

1 

— 

r 

A" 

2 


2((/  :♦" 


2 


2  (./   I:" 


\  Sec  Table  XX.  (p.  301)  for  scale  of  sizes  of  Type'*  C  " 

keel  plates. 


mild  steel,  and  without  welds.     Keel  plates  of  mild  steel. 


298  SHIPS'  BOATS 

the  hooks  were  never  tested,  either  practice  possessed  very  little 
value. 

Wrought  iron  lends  itself  better  for  welding  than  mild  steel, 
and  welding  the  shanks  of  steel  hooks  should  never  be  allowed. 
The  quality  of  the  weld  depends  on  the  workmanship,  and  the 
writer  must  confess  that  as  the  outcome  of  many  tests  to 
destruction  and  proof  tests,  failure  at  the  weld  is  quite  unusual. 
There  is  always  present  the  element  of  doubt.  The  lifting  hooks 
are  of  such  importance  and  have  to  be  subjected  at  times  to 
sudden  and  unequal  stresses,  that  the  question  should  not  be 
trifled  with  ;  good  workmanship  coupled  with  suitable  scantlings 
are,  therefore,  very  essential. 

An  interesting  comparative  test  was  carried  out  by  Messrs. 
Church  and  Turner,  smiths,  of  Greenock,  in  conjunction  with  the 
writer. 

Wrought-iron  lifting  hooks  of  circular  section  were  made  for 
a  28-ft.  lifeboat  of  Class  Ia,  the  scantlings  of  which  agreed  with 
those  in  Table  XIX. 

Another  hook  was  forged  from  the  same  material,  and 
its  section  was  worked  out  graphically  to  approximate  to  the 
correct  theoretical  pear  shape.  The  area  of  the  circular  section, 
and  that  of  the  pear  shaped,  were  checked  by  the  planimeter, 
and  the  two  made  to  agree,  so  that  the  sectional  area  of  the  two 
sections  were  identical.     The  comparison  is  seen  in  Fig.  166. 

The  results  of  the  tests  proved  to  be  very  interesting  but  at 
the  same  time  confusing. 

The  elastic  limit  of  the  circular  hook  was  greater  than  the 
pear-shaped  section,  but  the  ultimate  breaking  stress  was  greater 
in  the  latter  than  the  former.  The  real  strength  of  the  hook  was 
shown  in  the  extent  of  the  elastic  limit.  One  would  naturally 
expect  the  section  shaped  to  suit  the  theoretical  considerations, 
would  give  the  better  result,  but  this  may  be  explained  by  the 
fact  that  unless  the  material  at  the  flattened  out  portion  of  the 
hook  is  maintained  in  a  perfectly  true  axial  plane  in  a  line  with 
the  pull,  there  is  a  twisting  moment  which  is  detrimental  to  its 
efficiency.  All  derrick  and  crane  hooks  are  shaped  on  the 
principle  of  the  pear-shaped  section,  but  when  applied  to  the 
lifting  hook  having  a  long  shank,  the  advantages  are  not  verj'  great, 
and  in  ca^e  of  ordinary  standard  pulling  boats  the  question 
is  hardly  worth  considering,  especially  in  view  of  the  very  great 
difficulty  of  working  out  a  satisfactory  scheme  of  standardisation. 

If  the  scantlings  shown  in  Table  XIX.  are  adhered  to,  the 
lifting  hooks  will  stand  all  the  stresses  which  an  open  lifeboat  is 


LIFTING  HOOKS,  ETC. 


299 


likely  to  experience,  and  will  not  raise  doubt  in  the  minds  of 
ships'  officers  and  passengers. 

Keel  Plates. — There  are  at  least  three  tjrpes  of  keel  plates 
which  are  considered  suitable  for  attachment  to  the  shank  of  the 
lifting  hook ;  they  are  designed  so  as  to  stand  a  stress  slightly 
in  excess  of  that  taken  by  the  hook.     "  Out  of  sight,  out  of  mind," 


-  ELEVATION  - 


-   SECTION  - 


■f 
2 


IL  i. 


-   PLAN  - 
Fig.  1()9.— Type  *' A  "  keel  plate  for  lifting  hook. 


can  well  be  applied  to  keel  plates  which  are  usually  fitted  under 
the  platforms  of  end  lockers,  but  open  to  conditions  where  damp, 
etc.,  hav^e  a  detrimental  effect  on  their  lasting  qualities. 

In  the  case  of  open  lifeboats  of  Class  I.,  25  ft.  to  30  ft.  in  length 
inclusive,  which  are  not  lifted  by  davits  at  the  extreme  ends,  a 
very  satisfactory  type  of  keel  plate  is  illustrated  at  Fig.  169.  This 
consists  of  a  steel  plate  cut  out  from  an  ordinary  mild  steel  ship's 
plate  with  the  jaws  turned  up  to  suit  the  lower  end  of  the  shank 


300 


SHIPS'  BOATS 


of  the  lifting  hook.     This  plate  is  fitted  on  top  of  the  keelson  and 
security  is  made  by  screw  bolts  with  countersunk  heads  bearing 

on  a'plate  fitted  on  the 
underside  of  the  keel,  the 
nuts  being  hove  up  on 
the  keel  plate.  Care  must 
be  taken  to  see  that  the 
ends  of  the  screws  are 
cut  and  slightly  clenched 
over  nuts.  This  type 
of  keel  plate  has  the 
advantage  of  a  securing 
bolt  fitted  immediately 
at  the  centre  of  the 
shank  of  the  lifting 
hook,  in  a  direct  line 
with  the  pull.  The  nut 
can  be  hove  up  securely 

Fio.  I70.-Typo  "B  "  keel  plate.  ^^^^    ^^^  ^^^  «*  ^  ^^^ 

spanner. 
The  heel  of  the  shank  can  be  formed  into  an  eye  to  suit  the 
jaws  of  the  keel  plate  (as  shown  in  section  at  Fig.  169),  by  working 

half-round  iron  into  a 
bulb,  (illustrated  in  Fig. 
167),  then  flattening  the 
sides  to  suit  the  jaws  and 
AifiTz     -==i:z=rii       a  hole  drilled  to  take  the 

securing  pin. 

Satisfactory  tests  have 

been  carried  out  on  hooks 

formed    in   this   fashion, 

si^c^r^rcoo^re/rsoA^A  with  the  result  that  the 

shank  of  the  hook  frac- 
tured before  any  impres- 
sion was  made  on  the  eye. 
The  jaws  of  the  keel  plate 
prevent  the  hook  from 
turning,  and  there  is, 
therefore,  no  necessitv 
for  a  square  neck  in  t^he 


PLAN 


Fig.  171.— Typo  *'C"  keol  plat<\ 


latter  to  be  fitted  in  way  of  the  ganj^board. 

An  iilt(»rnatiye  method  is  often  adopted  in  the  Clyde  district, 
by  fitting  two  plato.s,  the  one  forming   the  jaws  being  joggled 


y 


LIFTING   HOOKS,  ETC. 


301 


under  the  plate  attached  to  the  keelson  in  the  ordinary  way, 
having  the  centre  bolt  as  a  means  of  securing  both  the  curved 
and  flat  plates.  Very  Uttle  material  is  saved  by  adopting  this 
principle,  but  a  great  saving  of  labour  and  cost  is  gain^.  How- 
ever, the  standard  method  is  considered  preferable. 

For  lifeboats  from  21  ft.  in  length  to  24  ft.  inclusive,  a  keel 
plate,  illustrated  in  Fig.  170,  is  considered  sufficient  for  the 
purpose. 

The  results  of  tests  prove  the  necessity  to  Umit  the  use  pf  this 
bridge  pattern  type  of  keel  plate  t/O  boats  not  exceeding  24  ft.  in 
length,  or  where  there  is  a  gi-eater  dead  load  on  the  lifting  hook 
than  39  tons. 

The  shank  of  the  bolt  is  screwed  at  the  heel  and  secured  by 
nuts  fitted  below  and  above  the  bridge,  with  a  spht  pin  inserted 
through'  the  lowest  nut  and  shank  of  the  bolt. 

Care  must  be  exercised  by  the  smith  to  preserve  a  perfectly 
fair  and  level  surface  on  the  bridge  clamp,  for  the  reception  of 
the  securing  bolts,  and  the  nuts  on  the  lifting  hook.  The  arrange- 
ment is  shown  in  Fig.  170. 

For  lifeboats  not  exceeding  20  ft.  in  length,  the  shank  of  the 
lifting  hook  is  carried  through  the  keelson  and  keel,  being 
screwed  into  a  plate  of  the  type  shown  in  Fig.  171.  The  plate  is 
slightly  coimtersunk  which  allows  the  end  of  the  shank  of  the 
hook  to  be  well  clenched  over. 

Table  XX.  specifies  the  various  dimensions  of  this  type  of 
plate  to  suit  the  different  lengths  of  lifeboats. 

TABLE   XX. 
Scale  of  Sizes  for  Keel  Plates  of  Type  '*  C  "  fob  Boats  20  feet  in 

LENGTH    AND   UNDER. 

To  be  read  in  conjunction  with  Fig.  171. 


Ixjngth  of  boats  In  feet. 


Position  of  ScantlinKS. 


A 
H 
V 
I) 


E 


19  and  20. 


V 
r 

23" 

4.r 


17  and  18. 

16  and  IjcIow. 

r 

r 

ir 

U' 

r 

r 

7  " 

7  ' 

n 

2}' 

2  * 

•*r 

4.r 

Arrangement     of     Securing    Lifting    Hook    at    Gangboard. — 

All  lifting  hooks  which  are  fitted  with  keel  plates  illustrated  in 


302  SHIPS'  BOATS 

Fig.  169,  viz.  Type  "  A,"  need  not  ha,ve  the  square  neck  in 
way  of  the  gangboard,  but  as  the  latter  is  somewhat  weakened 
by  being  cut  for  the  insertion  of  the  eye  at  the  end  of  the  shank, 
the  bolt  is  held  rigidly  in  position  by  the  aid  of  a  steel  plate,  J  in. 
in  thickness,  fitted  in  halves  and  recessed  into  the  gangboard, 
being  secured  by  six  bolts  with  nuts  hove  up  on  washers  fitted 
on  the  underside  of  the  gangboard.  The  screws  must  be  cut  and 
clenched  over  the  nuts.     This  arrangement  is  illustrated  in  Fig.  168. 

All  Uftmg  hooks  having  keel  plates  of  Type  "  B  "  and  "  C  " 
(Figs.  170  and  171),  are  required  to  be  forged  with  square  necks 
at  the  gangboard  to  prevent  the  hook  from  turning,  and  fitted 
with  a  plate  recessed  into  the  gangboard  for  half  of  its  thickness, 
and  well  secured  with  four  bolts,  in  the  same  fashion  as  previously 
described  for  the  larger  hooks.  The  type  of  plate  used  is  shown 
in  Fig.  168. 

It  is  necessary  to  give  every  support  to  the  lifting  hooks,  and 
relieve  the  stress  on  the  boat.  For  this  reason  the  gangboard 
is  made  of  the  same  material  and  thickness  as  the  thwarts, 
having  one  end  well  bolted  to  the  cross  thwart  and  the  other  end 
well  secured  at  the  apron,  and  to  a  cross  piece  attached  to  the 
rising.  A  slight  check  is  given  to  the  gangboard  when  crossing  the 
thwart,  as  illustrated  in  Fig.  83. 

The  lifting  hook  should  not  project  above  the  line  of  the  gun- 
wale, otherwise  it  would  prove  a  source  of  danger  from  passing 
ropes.  At  the  same  time  there  must  be  a  sufiicient  distance 
between  the  point  of  the  hook  and  gangboard  for  manipu- 
lating the  link  on  the  block,  and  a  Hmiting  dimension  has, 
therefore,  been  inserted  at  "  G  "  in  Table  XIX.,  giving  scantlings 
of  lifting  hooks. 

The  forward  hook  must  look  aft,  and  the  after  hook  must  look 
forward,  that  is  to  say,  both  Ufting  hooks  look  toward  amidships. 

Considerations  when  Boat  is  lifted  near  the  ends. — Special 
precautions  must  be  taken  when  the  lifeboats  are  lifted  at  the 
extreme  ends,  as  in  the  case  of  Welin's  Quadrant  Davits.  Reference 
should  be  made  to  Fig.  168.  The  fastenings  of  the  deadwbod, 
keelson  and  keel  need  to  be  carefully  considered  in  their  relation 
to  the  securities  of  the  keel  plate,  and  so  arranged  that  the 
fastenings  to  the  frame  combination  of  the  boat  may  serve  the 
double  purpose  of  also  securing  the  keel  plates  of  the  lifting  hooks. 

The  distance  between  the  lifting  hook  and  the  stem  or  stem- 
post  head  doponda  on  the  type  of  davit  fitted  to  the  vessel. 

In  all  cases,  whether  the  Ufeboats  are  lifted  near  the  ends  by  a 
special  type  of  davit  or  by  ordinary  radial  davits,  the  position  of 


LIFTING   HOOKS,   ETC. 


303 


the  lifting  hooks  should  be  obtained  from  the  shipbuilder,  before 
the  frame  combination  is  commenced,  to  enable  every  considera- 
tion to  be  taken  into  account  in  regard  to  the  securities. 

When  fitting  the  keel  plate,  the  lugs  should  be  of  sufficient 
length  to  allow  for  the  insertion  of  the  pin  to  take  the  heel  of  the 
lifting  bolt,  as  there  is  not  much  room  to  spare  between  the  planks 
at  the  extreme  ends,  particularly  forward. 

The  securing  bolts  are  arranged  square  to  the  keel  plate  so  as 
to  avoid  tapered  washers  under  the  nuts.  The  heads  of  the  bolts 
are  square,  or  oblong,  to  suit  the  bearding  of  the  stem,  which 
prevents  them  turning. 

If  it  is  desired  to  secure  the  bolts  through  the  stem-band,  the 
operation  is  one  which  necessitates  great  care.  A  batten  mould 
is  made  round  the  face  of  the  stem  giving  the  position  of  the 
bolt  holes,  and  the  information  is  transferred  to  the  stem-band, 
which  of  necessity  has  to  be  made  of  heavy  scantling  to  provide 
sufficient  bearing  for  the  bolt  heads. 


TABLE   XXI. 

Scale  of  Sizes  fur  Keel  Plates  when  Open  Boats  of  Classes  I.  and  III. 

ARE  Lifted  near  the  Ends. 

To  be  read  in  conjunction  with  Fig.  168. 


Length  of  boat  in  feet 


29  and  30       25-28 


21-24 


16-20 


Maximum    dead    load  on  lifting 
hooks  in  tons 

Thickness  of  keel  plaU's  in  inches 

Width  of  keel  plate  in  inches 


Securing  bolts 


i Inner 
I  Outer 


7-9 


H 


3 


2  (a    I 
2  (a    I' 


6-8 


2@i' 

2  (e  r 


3-9 


21 

4®  r 


2-3 

1 

2Ca.Y 

2  fe  r 


Distance  between  centre  of  lugs  and  bottom  of    keel  plate  to  be  sufficient 
to  allow  for  insertion  of  securing  pin. 


Before  the  keel  plates  are  made,  the  boatbuilder  makes  an 
inside  mould  to  the  curvatuce  of  the  deadwood  and  keelson,  and 
from  this  he  makes  another  mould  which  the  smith  can  apply  to 
the  keel  plate  durin^^  the  operation  of  forging.  The  keel  plate 
will  fit  dead-home  to  its  work,  if  this  precaution  is  taken. 

A  good  combination  in  way  of  the  keel  plates  is  shown  in 
Fig.  168.    The  keelson  is  nin  as  far  fore  and  aft  as  the  deadwooda 


304 


SHIPS'  BOATS 


will  allow,  suitable  breasthooks  and  floors  being  fitted  to  strengthen 
the  ends  of  the  boat  and  support  the  combinations  of  stem  and 
stempost. 

Bolts  must  be  cut  and  clenched  over  the  nuts,  and  this  pre- 
caution attended  to  before  the  planking  is  commenced. 

Special  attention  must  be  given  to  the  quahty  of  the  dead- 
ly 


/^::^LimNG  MOOM 


y/y 


THWAItr 


-A 


GANGBOARD 


•  R/S/i^6 


7;>VjV4/rr 


^ 


SECrtONAL    ELEVATION  — 


pA 


—  PLAN  - 


Fig.  172. — Method  of  fitting  the  lifting  hooks  when  lifeboat  is  carried  in  Wchn's 

overframo  davit. 


woods,  and  care  taken  in  arranging  the  details  for  the  full  thick- 
ness to  fay  on  the  planking. 

A  scale  of  sizes  of  keel  plates  to  suit  the  conditions  under 
discussion,  is  given  in  Table  XXI. 

Considerations  when  Boat  is  fitted  in  the  Welin  Overframe  Davit — 
When  lifeboats  are  lifted  by  and  stowed  in  the  "  Welin " 
overframe  tvpe  of  davit,  the  ([ucsticm  of  the  position  of  the 
lifting  hooks  has  to  be  specially  cronsideied. 

The  stowing  chocks  under  the  lifeboats  must  be  fitted  at  the 
quarter  lengths  of  the  boat  from  the  ends,  to  give  adequate  support. 


LIFTING  HOOKS,  ETC. 


306 


The  chocks  are  fitted  on  the  da  vita  in  the  case  of  the  "  overliame  " 
type,  so  that  the  liftiu-;  honks  are  immediately  above  the  stowage 
chocks,  i.e.  situated  one  quarter  the  lenf^th  of  the  boat  from  the 
ends.  The  position  makes  it  very  awkward  to  give  adequate 
support  to  the  hooks.  It  is  therefore  necessary  to  extend  the 
gangboard  to  the  second  thwart  from  each  end  and  well  secure 
them  with  bolts,  as  shown  in  Fig.  172, 

Such  a  position  for  the  lifting  hooka  is  ideal  to  secure  the  best 
support  for  a  loaded  boat,  but  it  interferes  with  the  seating 
accommodation,  and  it  necessitates  the  davit  being  made  to 
the  form  of  the  boat.  The  difficulties  referred  to  can  be  obviated 
by  the  fitting  of  a  central  supportmg  chock,  leaving  the  lifting 
hooka  to  be  placed  and  secured  in  the  usual  position.  This  re- 
arrangement interferes  somewhat  with  the  actual  purpose  of  the 
davit  in  giving  an  all-round  view  under  the  keel  of  a  boat  stowed 
on  the  Promenade  Deck. 

Lifting  Hooks  at  Extreme  Ends  ol  Boats. — All  lifeboats  are 
arranged  to  be  lifted,  if  possible,  from  the  keel,  but  there  may  be 


Ifio.  173,  Pro.  174. 

Lifting  hooks  for  Bmall  "Bquarr-sbrn"  boats. 

circumstances  which  prevent  this  rule  being  adhered  to,  owing 
to  the  position  and  arrangement  of  the  davits.  The  difficulty  is 
only  met  in  the  case  of  small  coasting  steamers,  where  a  "  square 
stem"  boat,  or  boats,  are  carried,  when  it  becomes  necessary 
to  arrange  for  the  lifting  hooks  to  be  fitted  to  the  sternpost. 

The  first  cfmsideratiou  is  to  strengthen  the   transom  and 
sternpost  head  beyond  the  usual  scautUngs.    The  latter  is  made 


306 


SHIPS'  BOATS 


to  mortice  into  the  cross  piece,  and  the  quarter  knecij  must  be 
substantial  and  well  secured  to  the  gunwale,  transom,  and  cross 
piece  with  clenched  fastenings. 

'  Figs.  173  and  174  illustrate  a  type  of  lifting  hook  which  has 
proved  satisfactory  in  the  case  of  small  boats.  The  former  is 
fitted  to  boats  of  about  20  ft.  in  length,  and  the  alternative 
arrangement  is  suitable  for  smaller  boats.  In  each  case  a  stout 
plate  is  secured  to  the  stempost  to  take  the  countersink  of  the 
heads  of  securing  bolts,  which  is  recessed  into  the  transom. 
Care  must  be  taken  in  forging  the  hook  and  drilling  the  holes  for 
the  securing  bolts,  to  provide  a  fair  surface  for  the  head  of  the 
nuts. 

The  arrangement  at  Fig.  173  involves  a  weld,  and  in  each  case 
the  bolt  must  be  subjected  to  an  approved  proof  test. 

Wire  Slings. — In  certain  classes  of   vessels,  such  as  trawlers, 
steam  lighters,  etc.,  where   the  statutory  regulations   demand 


*toof< 


Fig.  175. — Method  c»f  lifting  small  boat  when  stowed  under  a  derrick. 

only  one  boat  to  be  carried,  and  which  can  be  launched  quickly 
on  either  side  of  the  vessel,  it  is  usual  to  fit  the  boat  under  the 
main  derrick,  and  so  arranged  that  if  steam  is  off  the  winches, 
the  boat  can  be  swimg  over  the  side  without  having  to  top  the 
derrick.  In  such  a  case  a  suitable  wire  bridle  is  shackled  t-o 
ring  bolts  well  secured  to  the  stem  and  stempost. 

The  general  arrangement  of  sling  is  given  in  Fig.  175. 

Mousing  Arrangements  for  Lifting  Hoolu. — Fig.  170  illustrates 
the  McKays'  Patent  Safety  Hook,  supplied  by  Messrs.  H.  and  C. 
Grayson,  Ltd.,  Shipbuilders  and  Engineers  of  Liverpool,  which 
is  matle  on   the  same  princij)le  as  the  McKays*  Engaging  and 


LIFTING   HOOKS,  ETC. 


307 


Disengai^ing  Gear.  This  hook  has  found  favour  with  many 
shipping  companies. 

The  purpose  of  a  mousing  arrangement  is  to  prevent  the  falls 
from  losing  their  grip  of  the  hook  when  the  boat  is  waterbome, 
and  it  is  desired  to  keep  the  boat  alongside  the  ship.  Release 
is  obtained  by  hinging  the  mousing  gear  by  the  aid  of  the 
lanyard. 

In  Fig.  177  we  have  a  very  old  arrangement  which  was 
originally  termed  the  "  Angrove  "  patent.    The  point  of    the 


I :      ;        I'.! 


Tiir 


I"  • : 


UJ 


mr 


Fio.  176. — McKay's  patent  safety 
hook 


Fio.  177. — The  Angrove  patent 
mousing  arrangement. 


lifting  hook  is  formed  as  shown  in  the  illustration,  and  a  simple 
link  is  fitted  on  the  hook  which  prevents  the  falls  from  jumping 
off,  and  when  release  is  required,  the  tail-end  of  the  link  is  lifted, 
which  allows  the  head  to  clear  the  point  of  the  hook. 

In  both  of  these  arrangements  it  is  only  a  mousing  gear  that 
is  fitted  and  must  not  be  confused  with  a  disengaging  gear. 

Chain  Slings. — The  lifting  arrangements  for  a  large  motor  boat 
require  special  attention  and  consideration.  Owing  to  the 
position  of  the  machinery,  etc.,  it  is  not  always  practicable  to 
fit  fixed  hooks,  and  in  order  to  adequately  support  the  weight 


v^ 


*H'."?^'    ^''  iT 


'    « 


<»>» 


^ 

^ 


^' 


0t 


^  -= 


f 


^i*' 


T 

m 

« 


cur^^^  ^ 


1 1 


/; 


/: 


'  i  * 


^ 


^««^       « 


^       ^ 


* 


§34^ 


X 

V 
^ 

^ 


i 


•«  r*  • 


I 


/;/  tli'5  uiiuh\u*\ry  arirl  full  numlif^r  of  p^Ts^^as  m  the  boat  when 
\numf,  l"w«rMvl  inVi  til*,  wabrr,  chain  .slings  are  usually  fitted. 
A  *J«;Uil»'^l  iinii\\'jt*u\(ix\i  of  chain  slings  is  given  in  Fig.  178, 


LIFTING    HOOKS,   ETC.  309 

and  aizo.s  have  been  insertfld  whicli  are  considered  suificient  for  a 
de^  load  of  4  b>na,  The  forward  Igr  of  the  after  sling  ib  arraufijed 
at  the  heel  t«  clear  the  propeller  shaftint;  by  fitting  a  special 
shackle  and  keel  plate  as  shown  in  the  drawinj^. 

Steadying  chains  are  essential  fittings  to  prevent  the  hook  from 
falliiv;  and  keep  it  in  a  vertical  piano. 

The  drawback  t<i  a  system  of  chain  sliajis  is  that  the  lifting 
hook  is  not  a  fixture,  and  there  is  a  difhculty  at  times  in  making 
steadying;  chains  the  exact  length  to  suit  the  slings,  with  the  result 
that  there  is  a  certain  amoimt  of  slackness,  quite  sufficient  to 
give  the  occupants  of  the  boat  a  sense  of  insecurity.  If  there  is. 
any  movement,  the  boat  will  list  to  the  side  where  the  weij-ht  is 
the  greater. 

In  the  Admiralty  service  it  ia  the  standanl  practice  to  fit 
cliain  slings  to  the  motor  and  large  pulling  boats,  but  the  con- 
ditions in  a  passenger  vessel  are  very  different.  The  whole  of  the 
persons  lowered  in  a  boat  from  one  of  H.M.  war  vessels,  are  trained 
and  disciplined,  while  a  large  portion  of  the  occupants  of  a  lifeboat 
launched  in  an  emergency  from  a  passenger  or  emigrant  vessel, 
would  be  in  a  condition  of  excitemeqt,  and  the  difficulties  of 
controlling  and  releasing  the  boat  would  be  accentuated  by  the 
crowded  conditions. 

There  ia  little  doubt  that  chain  slings  can  be  arranged  to  sup- 
port the  weight  of  the  boat,  etc.,  to  better  advantage  than  can 
'  B  obtained  from  fixed  lifting  hooks,  but  taking  all  the  circum- 
stances into  consideration,  it  is  preferable  to  fit  the  latter  when 
the  arrangements  will  admit. 

Cliain  slings  are  always  fitted  to  the  open  boats  of  Class  II., 
and  pontoon  boats  of  Classes  Ic,  IIb  and  llo,  which  have  collap- 
sible bulwarks.  An  arrangement  of  fixed  hooks  in  these  types  of 
boats  and  those  of  Captain  Murray's  nested  boats  woidd  seriously 
interfere  with  the  stowage  arrangements.  The  various  details 
associated  with  the  lifting  gear  of  these  boats  have  been  dealt 
with  in  their  own  particular  section. 

Robinson's  Patent  Common  Hooks.— -Where  it  is  unnecessary 
to  fit  a  simultaneous  releasing  gear  to  ships'  boats,  a  very 
reliable  and  convenient  form  of  hook  has  been  designed  by 
Messrs.  Robinson  and  Co.,  Ltd.,  of  Chiswick,  London,  which 
enables  the  two  ends  t)f  the  boat  to  be  unhooked  separately  by 
hand  by  two  men. 

Illustrations  of  the  hook  are  given  in  Fig.  179  and  180,  from 
which  it  will  be  seen  that  the  book  is  of  the  fixed  or  no7i-tumblinq 
type,  and  attached  to  theshankbyabolt  Wabovethegangboard. 


no  SHIPS'  BOATS 

Tfe  —till  do  mat  adrocate  tkw  m  t 
maiilir  its  mCg faan  «f  book  for  indepcBdcA  I 

A  i|M(Mlhr  deN^aed  dwckfe  G  tt  made  to  fit  tfe  haafc,  i 
■  cmuieetod  to  Um  tag  bolt  of    tke  lava  tadde  Uoek.    Tb  ' 
pnnrcat  tlie  fab  bwwn^  detacbcd  £idib  tlw  hook.  «  «a^ 
■HMWDfE  attaagpnmi  m  fitted,  h  sbnn  >t  T.    Wbn  it  m 
neea—ry  to  nleMe  tlie  falk  btHB  tbe  hook,  •  Uunn  deviee  at  K 
M  ca*df  opetated  and  aflavi  tlie  lAacUe  to  cleat  tbc  hook. 


Fig.  179  tthiiwn  the  mousing  gear  in  position  to  prevent  1 
faliH  Irom  unhooldng,  and  Fig.  180  shows  the  gear  out  of  a    ' 
which  prevents  any  obstruction  to  unhooking,  or  hooldcg  ( 
the  "hsekle  attached  to  the  lower  tackle  block. 

This  type  of  hook  hsa  been  adopted  by  the  Britiah  Admiralty  1 
for  mII  biiatK  of  the  non -emergency  cla.ss  which  are  carried  uodcv  T 
davitA ;  it  liax  been  litted  in  a  large  number  of  Royal  fleet  i 
Auxiliaried  and  merchant  ve^HcLs,  and  from  the  perwnal  obaerva-  J 
tion  of  the  writer,  has  proved  very  satinfactory. 


BOATS'   ENGAGING  AND  DISENGAGING  GEAR    311 

SECTION  B.— BOATS*    ENGAGING   AND   DISENGAGING 

GEAR 

The  question  of  releasing  a  ship's  boat  from  the  overhanging 
fall9  attached  to  the  davit  blocks,  into  the  water,  is  one  of  very 
great  importance.  Accidents  have  occurred  to  both  passenger 
and  cargo  vessels  through  the  inefficient  means  provided  for 
quickly  detaching  the  boats  from  the  lifting  hooks. 

Considerable  difficulty  surrounds  the  subject  when  dealing 
with  the  equipment  of  lifeboats  on  vessels  in  the  Mercantile 
Marine  Service. 

Where  it  is  considered  necessary  to  fit  disengaging  gear  to 
boats  carried  on  war  vessels  of  the  British  Navy,  a  standard 
pattern  is  adhered  to.  The  reason  is  veiy  obvious.  Sailors  are 
trained  to  use  a  particular  type  of  apparatus,  which  obviates 
many  mistakes,  and  considerably  minimises  the  risk  which  is 
associated  with  the  operation  of  handling  a  gear  by  men  un- 
acquainted with  the  design. 

It  is  not  suggested  that  the  Bqard  of  Trade  would  go  so  far 
as  to  set  up  a  definite  standard  of  design,  and  thus  hinder  the 
scope  of  the  inventive  genius  of  the  private  individual,  but  such 
a  scheme  would,  nevertheless,  be  of  great  advantage  to  the 
mercantile  marine  and  increase  the  confidence  of  passengers 
in  the  ability  of  the  boat's  crew  to  successfully  manage  a  lifeboat 
in  difficult  circumstances. 

The  question  that  first  comes  to  one's  mind  in  dealing  with  this 
subject,  is  whether  it  is  necessary  or  essential  to  fit  a  disengaging 
gear  to  a  lifeboat. 

In  accordance  with  the  Rules  for  Life-saving  Appliances, 
means  must  be  provided  for  speedily,  but  not  necessarily 
simultaneously  or  automatically,  detaching  the  boats  from  the 
falls.  Where  the  falls  are  detached  by  hand  after  the  boat 
becomes  waterborne,  a  suitable  ring  or  long  link  is  fitted  to'  the 
lower  blocks,  so  as  to  provide  for  the  easy  detachment  from 
the  fixed  lifting  hooks  in  the  lifeboats. 

The  statutory  regulations,  therefore,  do  not  insist  on  a 
mechanical  means  being  fitted  for  releasing  the  boat  from  the 
blocks. 

There  have  been  many  types  of  apparatus  on  the  market 
which  were  supposed  to  satisfactorily  release  a  boat  under  service 
conditions,  which  have  failed  when  actually  tested  at  sea ; 
consequently  ships'  officers  are  somewhat  sceptical  as  to  the 
efficiency  of  some  releasing  gears. 


312  SHIPS'  BOATS 

Many  desi<i;n8  result  in  confusion  and  lack  of  confidence  on 
the  part  of  the  boat's  crew.  The  means  for  efEecting  release  is 
sometimes  provided  by  hauling  on  and  at  other  times  by  letting 
go  a  line.  Where  members  of  the  crew  are  not  constantly 
attached  to  the  one  ship,  these  differences  of  design,  in  the  operat- 
ing movement  of  the  various  gears,  create  difficulty.  In  any  case 
a  clear  and  simple  description  of  the  particular  gear  fitted  to  the 
boats  should  be  placed  ne^r  the  lifeboats,  and  the  crew  thoroughly 
trained  in  the  use  of  the  mechanism,  under  sea-going  conditions. 

The  nece^ity  for  fitting  a  mechanical  means  of  simidtaneously 
releasing  the  lifting  hooks  from  the  falls,  appeals  to  every  person 
who  possesses  sea  experience,  but  as  to  the  most  satisfactory  type 
of  gear,  there  is  a  difference  of  opinion,  for  associated  with  the 
releasing  operation  is  the  question  of  seamanship  in  controlling 
the  boat  and  preventing  her  from  being  drawn  under  the  stem 
of  the  vessel  and  coming  into  contact  with  the  propellers. 

It  is  of  paramoimt  importance  when  a  boat  is  lowered  into  the 
water  from  davits,  that  it  should  be  cleared  from  the  falls  as 
quickly  as  possible. 

When  release  is  actuated  by  hand,  the  process  lends  itself  to 
difficulty  and  danger,  unless  the  two  hooks  are  released  together. 

K  the  boat  is  lowered  when  a  heavy  sea  is  running,  there  is  a 
common  danger  for  the  forward  block  to  drop  below  the  lifting 
hook  and  so  become  released,  and  the  after  hook  to  remain  engaged 
with  the  link  in  the  block,  unless  an  arrangement  of  mousing 
the  hook  is  fitted,  which  prevents  the  link  on  the  block  from 
freeing  itself.  The  method  must  be  simple  and  effective,  for  the 
reasons  already  explained. 

If  the  ship  still  has  way  and  it  becomes  necessary  to  launch 
the  boats,  then  the  difficulty  of  releasing  the  falls  by  hand  is 
considerably  increased  ;  if  there  is  a  towing  stress  on  the  forward 
hook,  the  operation  of  disengaging  the  falls  is  accompanied  with 
some  risk,  unless  the  preliminary  precaution  is  taken,  before 
launching  the  boat,  to  secure  the  painter  to  a  cleat  or  stanchion 
on  the  deck  well  forward  of  the  davits  ;  so  that  when  the  boat 
becomes  waterbome,  the  effect  of  the  towing  stress  on  the  blocks 
can  be  relieved  by  hauling  on  the  painter,  which  would  then 
allow  the  link  to  clear  tlie  liook.  Here  again,  tlie  question  of 
scamansbi])  conies  in,  and  men  slunild  be  trained  to  disengage  the 
boat  under  those  conditions,  to  j)revent,  as  far  as  ordinary  cir- 
cumstances will  allow,  the  lifeboat  from  being  swamped  in  a 
storm. 

Comparatively  few  car^o  vessels   are  supplied    with    boats 


OATS'   ENGAGING  AND  DISENGAGING  GEAR    313 

fitted  with  enfjagint;  aud  disengaging  ^ear,  but  owiiit;;  to  the  ex- 
perience f;ained  during  the  European  War,  the  majority  ol  the 
standard  vessels  conetnicted  in  Great  Britain  are  fitted  with 
lifeboats  having  a  mechanically- controlled  releasing  gear. 

Most  of  the  leading  passenger  liners,  telegraph,  and  pilot 
VCBS^,  have  their  boats  fitted  with  disengaging  gear. 

General  conditions  are  now  laid  down  by  the  Board  of  Trade 
before  boats'  engaging  and  disengaging  gears  can  be  used  as  part 
of  the  statutory  equipment  of  a  ship.     They  are  as  follows  : — 

"  (1)  All  disengaging  gears  must  be  so  arranged  as  to  ensure 
simult-aneous  release  at  both  ends  of  tiie  boat. 

"  (2)  The  means  of  effecting  release  must  be  placed  aft,  bo  as 
tn  be  under  the  personal  control  of  the  coxswain  in  charge  of  thtt 
boat. 

"  (3)  The  gear  may  be  of  a  type  affording  release  before  the 
boat  is  waterborne,  as  well  as  when  the  boat  is  wholly  or  partially 
waterborne ;  or  alternatively,  it  may  be  of  a  type  affording  release 
only  when  the  boat  is  wholly  or  partially  waterborne.  In  either 
case  it  must  be  safe,  speedy,  and  reliable  in  action. 

"  (4)  The  action  should  be  such  that  the  hook  offers  no  resist- 
ance to  release  should  there  be  a  towing  strain  on  the  falls. 

"  (."5)  The  hooks  must  be  suitable  for  instant  imhooking  by 
hand. 

"(fi)  The  gear  and  mechanism  for  effecting  release  must  be 
such  and  so  arranged  as  to  ensure  the  safety  of  the  boat  inde- 
•  pendeutly  of  any  "  safety-pins." 

"  (7)  The  means  for  effecting  release  may  be  by  hauling  on,  or 
letting  go  a  line,  or  by  a  lever.  If  release  is  effected  by  a  pull 
upon  a  hne,  the  latter  must  be  properly  cased  in.  Rods  or  other 
connections  between  hooka  must  also  be  cased  in  whenever  this 
is  necessary  for  safety  or  for  the  efficient  action  of  the  gear  and 
the  protection  of  persona  from  injury. 

'■  The  fairleads  must  be  properly  arranged  to  prevent  the  bnea, 
which  shotdd  be  fitted  with  chains  where  necessary  for  efficiency, 
from  jamming  or  nipping,  and  must  be  strongly  attached  to 
permanent  parts  of  the  boat. 

"  (8)  Such  parts  of  the  gear  as  would  otherwise  be  likely  to 
set  fast  by  rust  or  corrosion  must  be  made  of  non-corrodible 
metal. 

"(9)  No  part  of  the  gear  taking  the  weight  of  the  boat  is  to  be 
made  of  cast  metal. 

"  (10)  The  scantlings  and  proportions  of  all  parts  taking  the 
weight  of  the  boat,  should  be  such  as  to  provide  a  factor  of  safety 


314  »SHIPS'  BOATS 

of  at  least  four,  with  a  dead  working  load  equivalent  to  the  total 
weight  of  boat,  equipment  and  full  complement  of  persons." 

All  new  sets  of  disengaging  gear  must  have  a  sample  of  each 
size  submitted  for  a  proof  test  equivalent  to  the  total  weight, 
including  equipment  and  full  complement  of  persons,  of  the  largest 
boat  for  which  it  is  claimed  the  gear  is  suitable. 

This  test  is  continued  to  the  point  of  fracture  in  order  to 
determine  the  approximate  factor  of  safety. 

Lowering  and  disengaging  tests  uniJi  a  loaded  boat  are  also 
carried  out  under  the  following  conditions  : — 

(a)  Boat  fully  waterbome. 

(6)  Boat  partially  waterbome,  one  end  being  out  of  the 
water. 

(c)  In  the  case  of  a  gear  which  can  be  released  before  the 

boat  is  waterbome,  additional  tests  with  the  keel  of  the 
boat  just  clear  of  the  water.  ' 

(d)  The  efficiency  of  the  hooks  and  gear  is  also  tested  by  well 

jerking  the  boat  in  the  tests  (b)  and  (c). 

If  the  results  of  the  tests  are  satisfactory  a  certificate  of 
approval  is  granted  to  the  owner  or  patentee. 

From  a  practical  working  point  of  view,  it  is  generally  con- 
sidered that  boats'  disengaging  gears  should  be  divided  into  two 
distinct  classes — 

(1)  Those  which  can  release  when  the  vessel  is  under  way  at 
ordinary  or  usual  speed. 

(2)  Those  which  release  when  the  vessel  is  almost  at  rest. 

In  deaUng  with  the  first  namexl,  the  gear  should  be  such  that 
when  the  vessel  is  steaming  at  the  rate  of  say  15  knots,  the  boat 
could  be  released  at  the  particular  moment  desired  by  the 
coxswain. 

With  a  heavy  sea  mniiin<s  it  is  verv  desirable  that  the  release 
should  be  instantaneous  and  simultaneous  at  both  ends.  The 
operation  of  release  must  be  under  the  control  of  one  person 
thoroughly  acquainted  with  the  mechanism  and  well  skilled  in  the 
handling  of  a  boat  when  launched  under  difficulties. 

On  all  well-equipped  passenger  vessels,  two  emergency  or 
**  accident "  boats  are  carried  near  the  navigating  bridge,  one 
on  each  side  of  the  vessel,  swung  out  while  at  sea,  brailed  into  a 
boom  and  ready  for  immediate  use.  This  is  a  regulation  issued 
by  the  Steamboat  Inspection  Service  of  the  United  States  of 
America,  and  is  adhered  to  in  most  British  passenger  ships. 

The  purpose  of  these  boats  is  that  in  the  case  of  persons  falling 
overboard,   or   for  other   reasons   of   emergency,   they  can   be 


BOATS'   ENGAGING  AND   DISENGAGING  GEAR    316 

rapidly  manned  and  lowered  into  the  water  at  the  word  of 
command  from  the  officer  in  charge  on  the  bridge. 

Special  men  are  selected  for  manning  these  particular  boats, 
and  the  number  of  crew  lowered  is  only  sufficient  for  the  proper 
handling  and  navigation  of  the  boat.  The  necessity  for  lowering 
the  boats  usually  occurs  when  the  vessel  is  under  way  with 
considerable  speed  ;  it  therefore  stands  to  reason  that  the  men 
qualified  to  manage  the  boat  should  be  well  trained  and  efficient, 
and  that  the  type  of  releasing  gear  should  be  such  that  it  can  be 
**  sUpped  *'  before  the  boat  becomes  waterbome,  for  any  towing 
stress  on  the  boat  when  the  vessel  is  rapidly  steaming  ahead  would 
inevitably  bring  disaster. 

The  enormous  weight  of  a  loaded  Ufeboat  brings  a  severe 
stress  on  most  types  of  gear  which  allow  the  boat  to  be  released 
before  being  waterbome. 

The  second  type  of  gear  referred  to,  viz.  that  which  releases 
when  the  boat  is  waterbome  after  the  vessel  has  come  to  rest,  is 
generally  considered  to  be  more  suitable  and  better  adapted  to 
the  needs  of  vessels  of  the  Mercantile  Marine  Service. 

In  case  of  disaster,  when  it  becomes  necessary  to  lower  the 
lifeboats  into  the  water,  they  would  probably  be  crowded  with 
passengers  in  a  condition  of  nervous  excitement,  having  just 
sufficient  crew  to  man  the  boat  for  rowing.  Under  these  con- 
ditions a  gear  which  can  be  released  before  the  lifeboat  reaches 
the  water  by  a  slipping  movement,  or  having  an  adjustment  of 
safety-pins,  would  be  a  source  of  danger  to  the  occupants, 
considering  the  great  distance  between  the  promenade  deck  and 
the  water-level  of  the  largest  passenger  vessels. 

The  purpose  of  lifeboats/  apart  from  the  emergency  boats,  is 
to  transport  the  passengers  from  a  vessel  which  is  probably 
foundering  and  has  little  or  no  way  on. 

During  the  operation  of  transferring  the  passengers  to  the 
boats,  the  personal  element  always  comes  into  operation  and  has 
to  be  carefully  considered.  It  may  be  possible,  under  the 
conditions  of  panic,  for  some  boats  to  get  launched  unattended  by 
sailors  qualified  in  the  use  of  releasing  the  falls  from  the  boat, 
and  if  there  is  a  heavy  sea  mnning  on  a  dark  night,  the 
congested  state  of  the  boat  may  prevent  simultaneous  action 
between  the  operators  at  the  lifting  hooks,  and  the  action  of  inde- 
pendently releasing  the  falls  will  be  accompanied  with  considerable 
danger.  It  is,  tlierefore,  considered  by  ships'  officers  that  a  simple 
device  for  simultaneously  releasing  both  ends  of  the  boat,  and 
under  the  control  of  a  responsible,  person  aft,  is  greatly  to  be 


316  SHIPS'  BOATS 

preferred,  and  not  so  liable  to  accident,  as  the  independent 
release. 

The  majority  of  the  "  waterbome  "  gears  will  not  successfully 
release  under  a  towing  strain  in  a  boat  loaded  with  the  full 
number  of  passengers.  The  various  patentees  claim  their  gears 
can  satisfy  the  requirements,  but  it  is  the  candid  opinion  of  the 
writer  that  if  a  boat  must  be  released  when  a  towing  stress  is  in 
operation  and  cannot  be  avoided,  then  the  first  type  of  gear 
referred  ido  is  considered  the  most  suitable,  and  it  possesses  the 
great  advantage  that  the  boat  can  be  dropped  at  the  psychological 
moment  to  catch  the  crest  of  a  wave,  and  thus  avoid  being 
swamped. 

However,  there  is  considerable  doubt  as  to  which  is  the  better 
type  of  gear  to  recommend  for  lifeboats  of  passenger  vessels  ;  it 
largely  depends  on  the  particular  d^ign  or  pattern,  and  each 
should  be  very  carefully  tested  and  treated  on  its  own  merits. 

Mills*  Patent  Engaging  and  Disengaging  Boat  Gear. — Messrs. 
William  Mills,  Ltd.,  Engineers,  of  the  Atlas  Works,  Sunderland, 
manufacture  an  apparatus  for  quickly  releasing  ships'  boats  from 
the  davit  falls,  and  which  has  found  much  favour  in  Great  Britain 
and  other  countries. 

A  general  arrangement  plan  of  the  gear  is  shown  in  Fig.  181. 
It  consists  of  a  straight  shank  lifting  bolt,*  the  heel  of  which  is 
formed  into  an  eye,  or  screwed  to  fit  the  particular  type  of  keel 
plate  suited  to  the  size  of  boat.  The  upper  portion  of  the  shank 
is  forked  and  well  secured  to  the  gangboard  by  nut  and  screw 
bolts.  Ordinary  screws  are  considered  unsuitable  for  the  purpose. 
Pivoted  to  the  fork  is  the  lifting  hook,  which  is  heavily  weighted 
at  the  lower  end. 

The  hook  does  not  project  above  the  gangboard,  and  the 
possibiUty  of  ropes  fouling  the  boat  is  therefore  minimised. 

The  position  of  the  head  of  an  ordinary  lifting  hook  above  the 
gangboard  is  about  10  in.  in  a  28-ft.  lifeboat,  or  2  in.  below  the 
gunwale.  To  maintain  the  same  conditions  of  safety  when  a  boat 
is  lowered*  with  the  lull  number  of  persons,  it  seems  essential  to 
fit  the  gangboard  in  such  a  position  as  to  allow  the  lifting  hooks, 
with  the  Mills'  Patent  Gear,  to  be  in  the  same  relative  position 
as  the  standard  type  of  lifting  liook. 

The  weighted  lever  maintains  the  hook  in  its  upright  position. 
Attaclied  to  the  block  is  a  circular  swivel,  link  or  eye,  which 
engages  tho  hook  bencmtli  the  level  of  the  gangboard.  The 
opcM'ation  of  connecting  the  hook  to  the  link  can  be  independently 
p(Mfornied  by  hand  at  eacli  end  of  the  boat,  or  the  hooks  can  be 


BOATS'  ENGAGING  AND  DISENGAGING  GEAR    317 


brought  into  position  simultaneously  by  the  coxswain  in  the 
stern-uhcots. 


Attached  to  tlie  w«if;hted  end  of  the  hook  is  a  chain  and  wire 
lead,  which  runs  tlirowgh  fairleads  secured  to  some  permanent 
j>art  of  the  structure.     These  releasing  wires  and  chains  have 


318  SHIPS'  BOATS 

usually  been  led  below  the  thwarts  and  side  seats,  or  below  the 
thwarts  and  in  front  of  the  tank  cleading.  This  is  a  matter  of 
detail,  but  with  the  lifting  hook  brought  up  to  the  same  height 
as  a  standard  hook,  it  is  a  more  convenient  and  practical  arrange- 
ment to  bring  the  leads  from  the  hooks  along  the  sides  of  the  boat 
above  the  thwarts.  This  is  the  general  practice  in  fitting  out 
boats  in  the  United  States  of  America  when  Mills'  gear  is  specified. 
In  any  case,  the  fairleads  must  be  well  secured,  and  so  fitted  as  to 
make  the  leads  as  easy  and  direct  as  possible. 

The  whole  of  the  apparatus  must  be  cased  in  to  prevent  any 
possible  interference  from  passengers  in  the  boat. 

The  disengaging  operation  is  under  the  personal  control  of  the 
coxswain  in  the  stem-sheets. 

The  boat  cannot  be  released  until  it  becomes  waterborne. 
Immediately  the  weight  bl  the  boat  is  reUeved  from  the  blocks, 
the  releasing  handle,  secured  to  the  chain  leads,  is  jmlled,  which 
raises  the  weighted  lifting  hook  lever  and  draws  back  the  point 
of  the  hook  clear  of  the  bridge  piece  attached  to  the  gangboard, 
and  thus  allows  the  link  of  the  block  to  free  itself. 

Great  care  must  be  exercised  by  the  boatbuilder  in  fitting 
up  the  gear,  to  see  that  the  length  of  the  chains  is  adjusted 
at  the  releasing  handle,  so  that  both  lifting  hooks  are  operated 
simultaneously.  The  patentee  depends  on  the  builder  following 
out  the  printed  instructions  issued  with  each  complete  set  of 
gear,  otherwise  a  careless  disregard  to  the  essential  points  to  be 
observed,  places  the  occupants  of  a  boat  in  great  danger. 

The  following  information  will  be  useful  in  selecting  the 
correct  type  of  gear  for  a  particular  weight  of  boat : — 

Type 

A 
B 

C 
D 

Dl  (steel) 

ROBINSON'S  BOAT-RELEASING  GEARS. 

These  are  of  two  kinds,  to  correspond  with  the  two  classes  into 
which  the  makers  contend  that  all  ships'  boats  should  be  divided, 
viz. : — 

1 .  Em^rcjetwji  Bonis,  for  lowering  instantly  while  the  ship  still 
retains  high  sjmmuI  (chiefly  to  pick  up  a  man  overboard). 


Weight  of  boat 

Size  of  swivel 

(with  full  complement). 

ring  in  bloek. 

.     2*7  tons. 

y  iron. 

4*1 

r 

.     5-5    „ 

r  steel. 

.     4-9    „ 

1" 

.     7-0    „ 

V 

BOATS'   ENGAGING  AND  DISENGAGING  GEAR    319 

Such  a  boat  has  (and,  of  course,  needs)  the  advantage 
of  skilled  control,  and  is  lowered  with  only  a  few  men 
on  board. 

2.  Ships*  LifeboatSy  for  saving  large  numbers  of  passengers 

and  crew  from  a  stranded  or  foundering  sjiip,  which  is 
presumably  either  stationary  or  has  little  way  on. 

3.  There  is  a  further  class  of  boat  used  either  under  safe 

conditions,  as  in  harbours  or  rivers,  or  by  people  too 
imskilled  to  be  trusted  with  any  simultaneous  gear,  or 
belonging  to  owners  for  whom  the  cost  of  such  gear  of  a 
reliable  pattern  is  prohibitive.     The  Robinson  patents 
*       provide  for  this  class  of  boat  by  a  special  form  of 
common  hook,  not  a  releasing  gear  in  the  proper  sense. 
Reference  has  already  been  made  to  this  in  Section  A, 
Part  VI. 
Robinson's  Navy  Releasing  Gear  is  designed  for  the  Emergency 
Boat.     It  is,  and  for  many  years  has  been,  carried  in  all  ships  of 
the  British  Navy,  and  is  no  less  suitable  for  the  two  emergency 
boats  which  first-class  passenger  vessels  ought  to  carry  in  addition 
to  their  "  lifeboats."     It  compUes  with  the  following  require- 
ments, which  are  practically  those  which  the  Admiralty  formulated 
many  years  ago  : — 

(a)  It  must  be  impossible  for  one  end  of  the  boat  to  release 

without  freeing  the  other. 
(6)  She  must  release  equally  well  whether  waterbome  or 
before  reaching  the  water,  at  the  discretion  of  the  man  in 
charge — because  she  is  liable  to  be  lowered  with  enough 
way  on  the  ship  to  swamp  the  boat  if  release  is  delayed 
until  after  she  is  waterbome.  Release  shortly  before 
reaching  the  water  involves  no  danger  if  the  boat  is 
well  handled :  (**  Automatic "  action  on  becoming 
waterbome,  which  means  the  automatic  opening  of  the 
hooks  as  soon  as  the  boat's  weight  is  off  the  tackles, 
is  obviously  inappUcable  if  the  ship  is  moving  fast,  as 
the  boat  is  then  liable  to  be  totued  by  the  tackles,  which, 
therefore,  are  no<  reUeved  of  her  weight.) 

(c)  The  hook  must  be  moused  against  accidental  imhooking 

if  the  boat  is  kept  lying  alongside,  but  the  mousing  must 
offer  no  hindrance  to  sUpping  or  to  hooking-on,  or  to 
unliooking  by  hand  if  desired. 

(d)  The  hook  must  be  in  the  boat,  not  on  the  tackle. 

In   the    Navy    the    emergency    boats    (formerly   called    the 
"  quarter-boats  "  because  one  was  carried  on  each  quarter)  are 


320  SHIPS'  BOATS 

large  cutters  fitted  with  "  cliairi  MJinf^a,"  for  which  a  spi^cial  design 
of  the  KobinsuQ  gear  is  used,     The  pitttera  (known  as  Type  C), 


which  is  fitted  in  some  other  classes  of  Navy  boats,  is  more  1 
suitable  for  mercantile  vessels,  and  is  shown  in  general  arrange-  • 


ment  in  Fig.  ISli,  while  the  hook  is  sJiown  in  elevation  in  Fig.  183 
(with  "  safety-pin "  in  place) ;  in  section  in  Fig.  184  (with 
safety-pin  removed) ;   in  section  (after  slipping)  in  Fig,  185.     It 


BOATS'  ENGAGING  AND  DISENGAGING  GEAR    321 

■  will  be  seen  that  the  weight  of  the  boat  tends  to  rotate  the 
tumbling  hook  H,  which,  however,  is  retained  in  place  by  the 
lever  K,  the  latter  being  held  to  its  work  by  the  direct  pull  of  the 
short  length  of  wire-rope  M.  The  ropes  M  of  the  two  hooks  are 
drawn  together  by  a  light  chain  fore-and-after  NN,  by  means  of 
the  tackle  shown  in  Fig,  182.    On  releaainij  tbe  fall  0  of  the  tackle 


— Section.     Relcuwd. 


both  hooks  are  set  free  to  "  tumble  "  and  ehoiild  do  so  instantly 
if  the  weight  of  the  boat  is  still  on  tbe  tackles,  or  if  there  is  even 
such  a  pull  upon  them  as  is  caused  by  the  rise  and  faU  of  the 
waves,  or  merely  by  pushing  the  boat  away  from  the  ship's  side, 
T  is  the  mousing  tumbler,  wbich  lies  in  the  mousing  position  by 
its  own  weight,  but  lifts  out  of  the  way  (and  then  falls  back  again) 
to  admit  the  ring  shackle  G  when  hooking  on.  (G  is  attached  to  the 
lower  tackle  block.)     T  can  be  turned  out  of  the  way  for  unhooking 


332  SHIPS'  BOATS 

by  ItaTul  by  a  touch  of  the  finger  upon  the  httle  lever  Q.  It  offers  1 
no  obstacle  to  slipping.  The  aectiona  show  the  naval  brass  pins  ' 
tor  the  hook,  etc.,  and  the  shouldered  rivets  holding  the  two  side-  ' 
plates  apart,  some  of  which  serve  as  stops  for  the  moving  parts. 
The  "  fin  "  on  the  top  of  the  hook  and  the  projection  below,  and 
that  on  the  lever  K,  all  serve  minor  purposes  in  ensuring  safe 
working.  W  is  a  bayonet-joint  pin  (or  bolt  and  nut)  to  enable 
the  hook  to  be  removed  if  desired,  leaving  only  the  head  of  the 
keel-bolt  above  the  deck.  Another  pattern  is  made  in  which  the 
hook  stands  less  high  above  the  deck.  It  will  be  seen  that  the 
fore-and -after  is  above  the  thwarts,  well  in  sight,  and  that  no 
one  can  do  any  harm  by  hanging  on  to  it  or  stumbling  against  it, 
as  that  can  only  tighten  the  pull  which  prevents  the  hooks  from 
tumbling  ;  this  marks  the  advantage  of  slipping  by  "  letting-go  " 
rather  than  by  pulling,  for  a  rope  which  has  to  be  pulled  can 
always,  in  effect,  be  pulled  accidentally  from  either  of  the 
causes  mentioned.  The  fall  0  is  given  a  turn  round  a  thwart, 
cleat,  or  bollard,  to  make  it  easier  to  hold. 

RQblnson's    Waterborne    Releasing    Gear    (Hercbant    Service) 
is  a  new  patent  designed  for  life-saving  boats,  in  the  sense  of 
boats  lowered  to  save  the  passengers  and  crew,  and  to  meet  the 
following  conditions  over  and  above  the  condition  that  it  must 
be  incapable  of  release  unless  the  boat  is  fully  waterborne  ; — 
(fl)  Such  a  lifeboat  is  hable  to  be  crowded  with  helpless  and 
frightened  passengers,  and  any  fore-and-aft  connection 
above  the  thwarts  may,  therefore,  be  subject  to  such  J 
interference  as  to  make  successful  action  impossible.    The  ] 
connection  must  be  down  below,  thoroughly  screened 
against  interference  or  contact  with  the  passengers'  feet. 

(b)  Skilled  control,  such  as  is  always  available  in  the  Navy, 

cannot  be  depended  upon  in  all  the  boats  of  a  large  . 
passenger  vessel,  and  the  less  skilled  man  who  may  be  , 
in  charge  cannot  safely  be  trusted  with  the  power  to 
slip  before  reaching  the  water,  In  the  confusion  of  I 
darkness  and  crowding,  and  amidst  the  terrors  of  s 
sinking  vessel,  tlie  boat  might  be  slipped  too  early,  with  I 
disastrous  result. 

(c)  The  two  hooks  must  be  connected  so  rigidly  that  they  not 

only  move  together,  but  so  that  moving  one  back  to 
the  hooking-on  position  inevitably  move*  the  otiiet  aa 
well,     Constant  readiness  for  hooking-on  is  important  f 
in  view  of  the  frequent  boat  drills  it  is  desirable  to 
courage.     In   Messrs.    Robinson   and    Co.'s    view   the  ] 


324 


SHIPS'  BOATS 


connection  between  the  hooka  ia  the  cmx  of t&e  mM 
and  it  will  be  seen  that  very  special  means  are  employed. 
The  hook  itaelf  is  shown  in  Fig.  186,  and  on  a  larger  scale, 
in  section,  in  Figs.  187  and  188. 

The  forward  hook  ia  similar  to  the  after  one,  but  without  the 
prolongation  of  the  link  R  to  form  the  releasing  lever  U,  which 
is  required  only  at  the  after  end.    When  the  lever  U  ia  raised  the  , 


link  B  is  drawn  downwards  and  cant^  the  hook  H  backwards,  so  J 
as  to  free  the  ring-shackle  attached  to  the  lower  block  G  1 
1  188).  The  treeing  action  is  assisted  by  the  lateral  1 
movement  of  B,  which  first  moves  backward  and  then  comes  j 
forward  to  push  ofi  the  shackle. 

The  Navy  mousing  tumbler  T  (slightly  changed  in  form)  ia  I 
retained,  and  Fig.  187  shows  how  it  lifts  out  of  the  way  in  the  act  1 
of  hooking-on.  Fig.  188  shows  the  shackle  completely  released  I 
by  the  continued  movement  of  the  lever  and  the  link  B. 


BOATS'  ENGAGING  AND  DISENGAGING  GE.Ut    325 

Two  galvanised  short^lmlc  crane  chaina,  X  and  Y,  are  attached 
to  R,  Piilliiif;  down  the  link  B  involves  pulling  up  chain  Y,  the 
other  end  of  which  is  attached  to  the  link  (B)  of  the  forward  hook  ; 
hence  both  Uoka  are  pulled  down,  and  both  hooks  are  freed,  by 
the  same  action.  Also,  on  the  lever  being  again  depressed,  both 
hooka,  through  the  action  of  the  chain  X,  are  re-set  for  hooking-on. 
The  catch  Z,  which  is  withdrawn  by  the  lifting  of  Q  in  taking 


W:^ 


Beleaaed. 


hold  of  the  releasing  lever,  preventa  the  latter  from  being  raised 
by  any  accidental  cause,  The  arrangement  of  the  lever  can  be 
varied  to  suit  the  construction  of  the  boat. 

An  ideal  connection  between  the  two  hooks,  to  ensure  absolute 
simultaneity  in  their  movement,  would  be  given  by  a  single  rigid 
rod  along  the  bottom  of  the  boat,  working  both  hooks  by  a 
suitable  arrangement  of  links  and  bell-cranks,  or  the  like,  all 
carefully  cased  in  against  injury  or  interference  by  the  crowded 
feet  of  the  passengers.     But,  unfortunately,  the  modem  practice 


326  SHIPS'  BOATS  ^^H 

of  hanging  boats  from  points  very  near  their  ends,  Bometni 
up  the  curve  of  the  stem  or  the  deadwood,  makes  such  a  c 
tion  difficult  and  incunvenicnt.  Messrs.  Robinson  and  Co., 
therefore,  use  chains  (two,  since  chains  can  be  used  in  tension 
only,  and  movement  both  ways  has  to  be  provided  for),  and  case 
them  very  simply  and  conveniently  by  running  them  through 
lubes:  1^  in.  galvanised  gas-pipe  of  good  quality  is  suitable. 
Each  chain  has  to  alter  its  direction  by  180°,  and  if  this  involved 
the  use  of  bell-cranks,  or  passing  the  chains  over  pulleys,  there 
would  be  no  gain  from  iising  them.  But  experience  has  shown 
that  if  such  tubes  are  bent  to  very  easy  curves,  chains  will  travel 
in  them  with  scarcely  any  more  friction  than  if  taken  round  pulleys, 
and  the  adoption  of  this  system  has  resulted  in  an  arrangement 
which  is  exceedingly  neat  and  simple,  while  the  protection  of  the 
chains  and  their  immunity  from  damage  or  interference  is  practi- 
cally perfect.     The  tubes  can  be  partly  filled  with  grease. 

Though  it  ia  impossible  for  the  coxswain  to  move  the  releasing 
lever  while  anything  like  the  weight  of  one  end  of  the  boat  is  on 
either  tackle,  there  is  enough  leverage  to  overcome  a  moderate 
towing  strain,  giving  a  pull  of  say  a  few  hundred  poimds.  It  is, 
of  course,  assumed  that  no  one  would  attempt  to  lower  a  heavily- 
weighted  lifeboat  while  the  ship  is  still  moving  at  a  really  con- 
siderable speed. 

The  tubes  are  clipped  to  the  sides  of  the  keelson  and  to  the  J 
linlcs  A  (which  take  the  place  of  keel  bottE),  and  it  is  not  neceesaiy  j 
t<j  avoid  bends  if  the  latter  are  e^iay. 

It  is  interesting  to  note  that  in  the  maker's  opinion  the  I 
widely  different  services  to  be  performed  by  the  Emergency  boat 
(for  the  man  overboard),  and  by  the  general  Life-aaving  boat, 
require  not  only  different,  but  diametrically  opposite  treatment, 
In  the  one  case  release  deferred  until  the  boat  is  waterbome  is 
dangerous  and  unsuitable  ;  in  the  other  it  is  ossectial  to  safety, 
Nearly  every  feature  of  the  gear  is  reversed  in  the  two  cases,  and 
the  reasons  given  for  this  are  weighty,  while  in  the  case  of  the  j 
Navy  emergency  boat  they  are  confirmed  by  the  succeeslul  1 
practice  of  many  years, 

THE    STEWARD    DAVIT    AND    EQUIPMENT    C0RP0RAT10H*S 
PATENT    BOAT    RELEASING    GEAR. 


The  action  of  this  gear  is  quite  different  to  those  previously  J 
described :  chains  and  wires  are  dispensed  with,  the  operating  1 
device  being  direct.     The  arrangement  consists  of  a  trippii^;  1 


BOATS'  ENGAGING  AND  DISENGAGING  GEAR^P 

or  tumbling  hook,  and  as  will  be  seen  from  Fig.  189,  these  hooka 
are  pivoted  to  a  bracket  which  is  strongly  attached  to  the  stem 
and  stempost.  The  British  Board  of  Trade  have  strong  objections 
to  lifeboats  being  lifted  from  the  extreme  ends,  but  this  gear,  now 
under  review,  can  easily  be  made  to  comply  with  all  the  require- 


Fii).    I8'J.— Thu   Stfward    UjiviC  and    E<iuinmeii 
rL'lL'iising  g<.ar. 


ments  whereby  the  stresses  are  taken  by  the  frame  combinationfl, 
and  the  heel  of  the  Uf  ting-hook  shank  secured  to  the  keelson,  keel, 
etc.  The  hook  is  operated  by  a  shaft  or  standard  pipe  running 
the  length  of  the  boat,  Brackets  with  shaft  bearer's  are  secured 
to  the  keelson  in  a  rigid  fashion,  but  with  suiUcient  clearance  and 
flexibility  to  prevent  binding,  should  the  shaft  or  keelson  com- 
bination become  distorted.     At  either  end  ol  the  pipe  there  is  an 


338  SHIPS'  BOATS  ^^H 

eccentric,  which  opetatea  a  cam.     The  latter  is  attached  to  a  ^ 
vertical  shaft,  the  upper  end  of  whicli  is  forked  and  fitted  with  a 
metal  roller.     When  the  horizontal  shaft  is  rotated  by  the  operat-    i 
ing  or  releasing  lever,  the  vertical  shaft  and  fork  are  drawn  down,    ' 
giving  release  to  the  honk  which  is  free  to  clear  itself  from  the 
shackle  attached  tu  the  davit  blocka,  even  when  there  is  a  towing    j 
strain  on  the  falls.     Fig.  189  illustrates  the  position  of  the  hook 
after  release.  I 

The  working  parts  of  the  gear  are  made  of  non-corroaive  metal 
or  of  galvanised  steel.     The  hook  pins  and  the  rollers  attached 
to  the  fork,  which  are  secured  to  the  upper  ends  of  the  vertical 
ahaftfi,  prevent  the  hfting  hook  from  tripping  before  the  coxswMn   I 
operates  the  lever,  and  are  made  of  special  "  monel "  metal. 

The  whole  operation  of  releasing  the  boat  from  the  falls 
becomes  extremely  simple  with  this  particular  design  of  gear,  as  I 
it  is  direct  in  action  ;  all  the  fittings  are  open  for  inspection,  and 
can  always  be  seen.  No  danger  is  present  during  the  operation 
of  lowering  the  boat,  imless  the  gear  collapses  or  an  individual 
deliberately  raises  the  operating  lever,  but  the  patentees  appear 
to  have  B^eguarded  their  own  interests  as  well  as  those  of  the 
passengers,  in  this  respect. 

The  boat  can  be  released  by  hand  when  waterbome,  in  the 
usual  way,  and  mousing  arrannements  are  fitted  on  the  hooka  ] 
to  prevent  the  links  on  the  blocka  from  premature  detachment.  I 

The  requirements  of  the  British  Board  of  Trade  are  very  severe, 
and  it  will  be  of  general  interest  to  the  reader  to  give  an  outline  of 
tests  carried  out  in  the  presence  of  the  writer  on  the  s.s,  Free- 
man in  Messrs.  Robins'  Ship  Repairing  Yard  at  BrookljTi,  New 
York. 

A  26-ft.  steel  lifeboat  capable  of  accommodating  about 
3-5  persons  was  fitted  with  the  Steward  Patent  Disengaging  Gear. 
The  boat  was  under  the  Steward  Patent  Davit. 

The  order  of  the  tests  was  as  follows  ; — 

1.  The  boat  was  lowered  into  the  water,  and  when  fully 
waterbome  the  gear  released  the  boat  from  the  falls. 

"1.  The  boat  was  hoisted  well  clear  of  the  water,  lowered,  and  , 
checked  suddenly,  jerked  fore  and  aft  by  means  of  the  falls,  and  i 
then  released  when  the  keel  was  about  two  feet  from  the  water-  ' 
level.     (See  Fig.  190.) 

3.  The  boat  was  partly  waterbome,  and  the  operating  lever  ■  | 
moved  slowly,  to  prove  that  both  ends  were  released  satisfactorily. 

4.  The  after  end  of  the  boat  was  waterbome,  and  the  forward  I 
end  lifted  out  of  the  water,  to  demonstrate  the  effect  of  a  towing  A 


BOATS'  ENGAGING  AND  DISENGAGING  GEAR    329 

strain  on    the  forward    hook.      No  difficulty  occurred   in  the 
releasing  operation. 

5,  The  boat,  when  floating  and  ei^aj^ed  with  the  falls,  was 
unhooked  by  hand,  while  the  gear  remained  locked.  Blocks 
were  again  engaged  by  hand  with  the  hftinj;  hoijks.  tn  demonstrate 


that  the  whole  operation  could  be  performed  by  two  men  in  a 
very  few  seconds. 

6.  Witi  the  boat  fully  loaded  with  over  thirty  men,  and  a 
number  of  the  occupants  standing  on  the  fore-and-aft  hollow 
shaft  or  pipe,  the  gear  easily  released  the  hooks. 

7.  The  final  test  was  a  severe  one  for  the  davits.  The  fully 
loaded  boat  was  raised  until  the  keel  became  well  clear  of  the 
water  ;  under  this  condition  the  operating  lever  was  raised;  and 


330 


SHIPS'   BOATS 


the  boat  released  without  difficulty.    The  photograph  shown  iif 
Fig.  190  illustrates  the  position  of  the  boat  immediately  afttrfl 
release. 

There  are  several  other  gears  on  the  market  which  appear^ 
fulfil  the  requirements  of  the  British  Board  of  Trade,  but  it  is 
considered  that  sufficient  reference  has  been  made  in  this  section  to 
actual  gears  now  in  operation,  and  also  tu  the  teste  carried  out,  to 
give  the  reader  a  general  idea  of  the  requirements  which  enable 
a  boat  to  successfully  take  the  water  after  being  released  from 
the  lower  blocks  attached  to  the  davit  falls. 


SECTION  C— CONSTRUCTION  OF  BUOYANCY  AIR-CASE 

All  lifeboats  must  be  in  possession  of  a  certain  amount  of  resetvi 
buoyancy.  The  open  hfeboats  are  fitted  with  buoyancy  air-j 
cases  along  their  sides,  and  the  pontoon  lifeboats  are  dependeafc; 
on  a  number  of  watertight  compartments,  which  are  an  integral! 
part  of  the  hull. 

The  internal  buoyancy  tanks  of  Class  Ia  and  Ib  lifeboats  aw; 
usually  constructed  of  the  best  quality  copper  or  yellow  metali 
of  not  less  than  18  oz.  to  the  superficial  foot.     The^  are  placi 
along  the  sides  of  the  boat  under  the  side  benches. 

It  is  admissible  to  fit  buoyancy  air-tanks  at  the  ends  of  a  boal 
but  never  in  the  bottom.  Although  it  is  an  inconvenience  to  fit 
a  buoyancy -tank  at  the  forward  or  after  ends,  as  it  interferes  wif ' 
the  stowage  of  equipment  and  the  fitting  of  the  lifting  hooks,  yi 
an  air-case  in  the  fore  end  has  the  advantage  of  giving  Ufting  powi 
to  the  boat  should  the  latter  become  flooded  with  water. 

Wlien  cases  are  fitted  in  the  ends,  they  should  be  separate^l 
into  two  distinct  portions  on  each  side  of  the  lifting  hool 
to  prevent  the  latter  being  unshipped  when  it  becomes 
to  remove  the  buoyancy  air-cases  for  inspection. 

The  method  of  construction  of  buoyancy  air-caaes  is  briefi^ 
described  as  follows  : — 

The  size  of  acopperor  Muntz  metal  sheet  supphed  to  the  tank- 
maker  is  usually  4  ft.  by  3J  ft.,  and  weighs  about  25'2  om., 
which  conforms  to  the  requirements  of  the  Board  of  Trade, 
18  ozs.  to  the  superficial  foot. 

From  the  information  supphed  to  him  by  the  boat-buUd< 
the  tank -maker  knows  the  internal  capacity  of  the  boat.  In  tiiia 
connection  it  is  well  to  remember  that  all  open  lifeboats  vi 
Class  Ia  should  be  coustmcted  with  a  coefficient  of  not  leas  thaa 
6i,   which   means  that  the  internal  capacity  divided  by  the^ 


>za.. 


mk  JL 


CONSTRUCTION  OF  BUOYANCY  AIR-CA8E8     331 

apparent  unit  of  capacity  exceeds  the  actual  number  of 'persona 
which  can  be  comfortably  seated  in  a  boat.  As  an  example, 
■  take  an  open  lifeboat  28-0'  X  8-5'  X  3y',  which  will  give  a 
capacity  of  about  540  cub.  ft.  The  number  of  poraons  which 
a  be  appropriated  ia  about  fifty.  The  number  of  cubic  feet 
of  buoyancy-tanks  must  therefore  be  fifty-four  and  not  fifty. 

The  amount  of  buoyancy-tank  capacity  depends  on  the  boat 
capacity,  and  not  on  the  number  of  persona  carried. 

The  tank-maker  usually  haa  standard  moulds  to  suit  the  shape 
of  the  bilge  of  ordinary  pulling  boata,  but  in  the  case  of  motor 
boats,  open  boats  of  Class  11. ,  and  nested  boats,  it  is  necessary 
to  make  special  moulds  to  suit  the  form  of  boat. 

The  end  sections  of  the  metal  air-cases  are  cut  to  the  shape 
given  by  the  moulds,  with  the  addition  of  a  margin  of  about  J  in. 
to  allow  for  the  single  hook  joint.  A  gauge  mark  is  then  made 
round  the  three  edges,  and  the  comers  cut  as  shown  in  Fig.  191  A. 

The  sectional  pieces  are  then  placed  in  an  edging  or  flanging 
machine,  whicli  flattens  and  stifTeus  the  material.  The  gauge 
marks  on  the  straight  edges  are  set  to  the  grips  of  the  machine, 
and  by  the  aid  of  the  lever  brought  up  to  the  horizontal  position, 
the  straight  edges  are  turned  up  to  a  rij^ht  angle.  The  curved 
edge  has  tu  be  treated  separately  by  hand  at  the  bench,  until  the 
section  takes  the  form  as  illustrated  in  Fig,  191  B. 

The  edges  of  the  end  sections  are  turned  over  by  hand  in 
hook  fashion  as  shown  in  Fig,  191  o,  ready  for  the  reception  of  the 
sides  of  the  air-cases. 

The  sides  of  the  metal  air-cases  usually  require  two  longitudinal 
joining  seams,  which  are  brought  together  with  double  hook 
joints.  The  material  is  placed  in  the  edging-machine  and  the 
hook  formed  in  the  one  movement  by  the  operation  of  the  lever 

I  brought  to  the  vertical  position.     The  edges  of  the  two  separate 
sheets  of  metal  are  thus  made  tu  hook  into  one  another  as  shown 
in  Fig.  191  d.     The  completion  of  the  double  hook  joint  is  made 
with  a  stamping-tool,  which  brings  the  hooks  into  close  joint, 
and  the  sides  into  hne  as  shown  in  Fig.  191  b. 
In  the  final  treatment  a  wooden  mallet  is  used,  followed  by  a 
steel  hammer  which  makes  a  tight  joint. 
Similar  procedure  is  followed  in  making  the  coimections  of  the 
aides  and  end  sections,  except  that  the  joints  are  only  of  the  single 
hook  type. 
All  the  joints  and  comers  are  carefully  soldered.     Great  care 
should  be  taken  with  the  closing  of  the  comers,  tor  it  is  here  where 
leakage  is  usually  discovered. 


332 


SHIPS'  BOATS 


When  the  tank-makers  understand  that  every  buoyancy  air- 
case  has  to  be  water-tested,  it  naturally  makes  them  careful  as 
to  the  quality  of  the  joints. 

The  width  of  the  hook  joints  should  not  be  less  than  §  in. 


B 


] 


F  G 

Y\Q,  191. Method  of  constructing  metal  buoyancy  air-oases. 

Tanks  must  not  exceed  4  ft.  in  length,  and  where  they  are 
more  than  3  ft.  6  in.  in  length  a  divisional  bulkhead  should  be 
fitted  at  the  half-length  for  stiffening  purposes.  This  is  some- 
times  done  by  inserting  a  skeleton  bulkhead  made  of  hardwood 
battens,  properly  secured    by  fore-and-aft  stays    to    prevent 


CONSTRUCTION  OF  BUOYANCY  ATE-CASES     333 

movement.  jVn  improved  method  is  to  fit  a  metal  divieional 
bulkhead  secured  by  small  angle  bigs  and  soldered  to  the  sides  of 
the  air-casG.  (See  Figs.  191  f  and  g.)  An  alternative  method  ia 
to  corrugate  the  sides,  which  appears  to  satisfy  the  requirements 
oi  the  wat«r  teat,  provided  the  depth  of  the  tank  ia  within 
reasonable  limits. 

The  writer's  experience  has  proved  that  4  ft.  is  far  too  great 
a  length  for  buoyancy-tanks.  They  cannot  be  inserted  between 
the  thwarts  under  the  side  benches,  without  making  portable 
the  sohd  support  under  the  thwart  fitted  in  line  with  the  tank 
cleading,  which  is  considered  very  undesirable.  The  tanks  have 
I  be  periodically  inspected,  and  it  is,  therefore,  necessary  to 
make  them  easily  removable ;  three  feet  is  considered  to  be  the 
maximum  length  for  general  utility  purposes. 

The  material  from  which  the  buoyancy -tanks  are  made 
should  be  periodically  inspected  for  surface  defects^  and  strips 
cut  and  tested  for  ductifity. 

The  manufacturer's  stamp  must  always  be  inserted  on  the 
yellow-metal  aheeta,  and  the  latter  should  occasionally  be 
weighed  to  ascertain  if  they  fulfil  the  requirements  aa  to  weight 
and  thickness,  viz.  not  less  than  18  ozs.  to  the  square  toot. 

There  is  more  in  this  question  of  surface  inspection  than  one 
would  imagine.  The  boatbuilder  or  tank -maker  has  no  guarantee 
from  the  metal  merchant  as  to  the  quality  of  the  material  beyond 
the  insertion  of  the  trade  stamp.  It  is  the  opinion  of  many 
builders  that  it  would  be  preferable  for  the  sheeta  to  be  inspected 
and  samples  tested  before  the  whole  of  the  material  is  delivered. 

Defective  tanks  are  a  source  of  great  danger  to  the  boat. 
Zinc  and  galvanised  iron  are  corujidered  unsuitable  for  the  purpose 
of  air-cases  or  buoyant  apparatus. 

Instances  have  occurred  during  the  survey  of  old  boats  when 
taking  out  the  buoyancy  air-caaes  for  inspection,  when  it  ha» 
been  found  that  some  of  the  tanks  have  become  defective  and 
leaky. 

The  boat  during  the  voyage  has  probably  been  flooded  to 
keep  the  planking  tight,  with  the  result  that  the  buoyancy 
tanks  have  become  fidl  of  water.  In  course  of  time  the  defective 
joint  has  mated  up,  retaining  the  water  inside  the  tank,  destroying 
the  purpose  of  the  air -case,  and  endangering  the  stability  of  the 
boat.  The  necessity  for  water-testing  each  individual  tarJi  before 
delivery  to  the  boatbuildeY  ia,  therefore,  obvious. 

Metala  which  have  been  cold-worked  are  sometimes  Uable 
to   what  ia  termed   "  seaaon-crackifig,"  which   only  makes  an 


334 


SfflPS'  BOATS 


appearance  after  the  material  has  been  worked  up  into  buoyant 
air-caeee,  particularly  when  the  sheets  have   been   exposed 
heat  or  come  into  contact  with  some  corroBive  element. 

An  interesting  example  of  the  defect  recently  came  before  the 
writer's  notice.  A  set  of  yellow-metal  tanks  had  paBsed  through 
the  test  tank  filled  with  wat«r ;  the  result  of  the  test  gave  no 
evidence  of  leak^e,  and  a  superficial  inflpection  showed  no 
material  defects.  The  tanks  were  expo.sed  id  the  sun  to  dry, 
then  placed  in  position  behind  the  cleading  in  the  lifeboat«,j 
Several  weeks  elapsed  when  the  tanks  were  removed,  and  it 
then  discovered  that "  season-cracking ' '  had  developed,  the  tai 
were,  therefore,  useless  for  the  purpose  for  which  they 
intended. 

Several  reaaona  may  account  for  the  development.  The  test 
tank  was  exposed  to  the  open  air  and  adjacent  to  the  roof  of  a 
building,  where  it  was  quite  possible  for  water  from  the  roof  to 
find  its  way  into  the  tank.  In  all  probability  there  was  acid  in 
the  water,  and  the  pressure  exerted  on  the  buoyancy  air-case 
during  the  test  opened  out  the  season-cracks,  allowing  the 
corrosive  efiect  of  the  water  to  complete  the  damage. 

Testa  were  taken  on  strips  cut  immediately  in  way  of  th< 
defects,  which  showed  the  material  to  be  shghtly  brittle,  but  th< 
metal  was  quite  good  in  other  parte. 

In  the  majority  of  cases  of  defects— the  cratjking  was  started  byj 
superficial  corrosion,  the  attack  of  the  corroding  agent  separatiiu[j 
the  crystal  grains  of  the  surface  layer,  the  result  being  veiy 
similar  to  a  crack. 

A  rough  surface  on  the  metal  sheet  immediately  raises  one' 
suspicion  as  to  the  quahty,  and  to  a  practical  man  the  colour  is  »■' 
good  indication  and  frnide. 

The  weight  of  the  completed  buoyancy -tank  runs  out  to  about> 
5  lbs.  per  cub.  ft. 

Precautions  must  be  taken  to  keep  the  air-casee  oft  the  rooves 
and  other  fastenings  in  the  boat,  by  fitting  rubbing  strips  attached 
to  the  timbers.  The  cases  should  also  be  placed  in  such  a  position 
aa  to  enRire  the  lifeboat  floating  on  an  even  keel.  They  must  also 
be  secured  in  place  to  prevent  lateral  movement. 

A  simple  method  tor  providing  means  for  testing  the  air-cases 
ia  by  filling  with  water  a  tank  of  sufficient  size  to  take  the  largest 
air-caae.  Insert  one  end  of  the  case  under  a  Icd^e  or  stop  attached 
to  the  tank,  and  bring  down  the  other  end  by  hand  pressure,  so 
that  the  whole  of  the  air-case  is  submerged.  If  there  are  any 
defects  they  will  immediately  show  themselves  by  the  appearanca. 


>at8^H 


CONSTRUCTION  OF  BUOYANCY  AIR-CASES     335 

ot  air  bubblee.  Turn  the  air-caae  end  for  end  and  again  inimeree. 
This  nob  only  teats  the  air-case  for  water-tightneas,  but  alao  for 
strength  and  rigidity. 

When  the  buoyancy-tank  is  completed  it  is  thfl  usual  practice 
to  insert  a  smalt  tube  and  inflate  the  tank  under  air  presaure, 
afterwards  soldering  up  the  hole.  In  pasaii^  the  cases  through 
the  tank,  the  rounded  surface  sometimes  becomes  distorted ;  the 
dodge  to  rectify  this  difficulty  is  to  place  the  metal  case  in  front 
of  the  stove,  when  the  internal  air  becomes  heated  and  expands, 
forcing  the  metal  back  to  its  original  shape.  If  the  air-cases  are 
kept  within  reasonable  dimcnaiona  there  should  be  no  necessity 
for  this  practice. 

In  some  shipbuilding  and  boatbuilding  yards,  buoyancy- 
tanks  are  not  only  tested  for  air-tightneas,  but  are  measured  for 
capacity  by  displacement,  the  one  operation  serving  the  double 
purpose. 

The  test-tank  ia  of  rectangular  shape,  and  the  horizontal 
internal  area  is  so  arranged  as  to  take  the  maximtmi  permissible 
lei^^th  of  air-case,  with  a  suitable  breadtii,  giving  12  sq.  ft.  A 
brass  sliding  scale,  decimally  divided,  is  attached  vertically  to  the 
inside  of  the  tank  near  the  water-level. 

A  wooden  grating  is  suspended  from  a  crane,  upon  which  are 
placed  iron  weighte.  These  are  lowered  into  the  water.  The 
zero  mark  on  the  scale  is  then  placed  at  the  new  water-level,  and 
the  grating  with  the  weights  removed  from  the  tank. 

The  air-caae  ia  then  placed  in  the  water,  and  the  weighted 
grating  lowered  until  the  air-case,  grating  and  weights  are  com- 
pletely immersed.  The  reading  on  the  scale  at  the  new  water-level 
will  give  the  volume  of  the  air-case  in  cubic  feet. 

This  method  gives  the  actual  cubic  capacity  of  the  air-case, 
and  may  result  in  a  small  saving  of  copper  or  yellow-metal  in  the 
large  cases,  as  compared  with  those  measured  in  the  usual  way. 

The  operation  of  testing  under  these  conditions  takes  con- 
siderable time,  as  the  water  after  each  immersion  of  the  tank  has 
to  become  perfectly  still  before  the  scale  readings  can  be  taken 
with  any  degree  of  accuracy  ;  consequently,  the  prevaiUng  method 
is  to  simply  immerse  the  air-case  in  a  water  tank  for  the  airtight 
test,  and  measure  it  for  cubic  capacity  by  Simpson's  Rule, 

The  following  is  an  example  of  the  formula  used,  and  is  fairly 
accurate  when  applied  to  straight-sided  tanks  of  ordinary  form, 
but  when  the  cases  are  curved  as  in  nested  boats,  or  of  peculiar 
shape  when  placed  in  the  ends  of  boats,  this  method  is  not  reliable, 
and  the  actual  capacity  should  be  obtained  by  displacement. 


336 


SHIPS'  BOATS 


Reference  should  be  made  to  Fig.  192. 

Area  of  Section  A  =  ^(a+  46) 

D' 
Area  of  Section  B  =  —  (a  +  46) 

6 


,,  I          £    .         •     area  of  Section  A  +  area  of  Section  B      . 
Volume  of  air-casc  = ^ X  L 


I'f 


i 


j.._ 


Via.  102 


Fio.  193. 
^(otho<l  of  measuring  buoyancy  air-cases. 

The  leiij^th  must  be  taken  from  end-to-end  sections,  and  not 
from  tlio  cdf^e  of  liook  joint.    (See  Fig.  193.) 

Example. 
Section  A  =-  D  ^  IS',  a  =  10',  6  =  -85' 

Section  B    -i)'  ==  1-2',  a  =  -65',  6  =  -55' 
L  =  --  3-5' 


1-8 


Area  of  Section  A  ----      {I'O  +  34)  =  •3(4-4)  =  1-32  sq.  ft. 
Area  of  Section  B  ■---  ^,-  (-65  -h  2-2)  =  •2(2-85)  =  -57  sq.  ft. 


1"32  +  -57      „  . 
Volume  of  air-casc=  —  ., X  Ao 


1 -89 -X  3-5  =  3-3  cub.  ft. 

9 


^L      an 


CONSTRUCTION  OF  BUOYANCY  AIR-CASES     337 

Wooden  aiT-cnses  are  not  allowed  to  be  inserted  in  tte  life- 
boate  of  a  vessel  engaged  in  the  ForeifSi  Trade,  but  they  were 
permitted  in  Home  Trade  vessels  during  the  period  of  the  war,  if 
boatbuilders  or  shipbuilders  wished  it. 

There  is  a  gceat  amount  of  labour  in  building  these  air-cases 
to  suit  the  form  of  boat  and  the  required  capacity. 

The  construction  of  air-eases  is  practically  a  trade  in  itself, 
requiring  an  expert  to  fix  suitable  sizes  for  the  particular  boat 
to  be  built ;  consequently,  the  demand  for  wooden  eases  is 
restricted.  They  are  heavier  than  metal  cases,  and  require  a 
much  greater  length  of  time  for  conatruction.  The  material  is 
cheaper,  but,  generally 
speaking,  wooden  cases 
are  unsatisfactory. 

The  Board  of  Trade 
have  issued  instructions 
for  the  construction  of 
wooden  air-cases. 

In  the  first  place 
the  material  must  be 
of  very  special  quality 
and  well  seasoned, 
usually  of  yellow  pine, 
3-ply  wood,  or  other  , 
suitable  wood ;  quite 
free  from  shakes  and 
knots.  Heartwood  should  be  carefully  avoided,  owing  to  its 
tendency  to  spUt. 

The  thickness  of  the  sides,  if  not  made  from  3-ply  wood, 
is  not  to  be  less  than  g-  in.  The  ends  are  made  of  elm,  or  an 
equivalent  hardwood,  not  less  than  I  in,  in  thickness,  with 
longitudinal  stiSeners  1}  in.  by  J  in,  of  white  or  red  pine  fitted 
at  the  comers,  to  form  the  framework  upon  which  to  build  the 
case. 

Laid  over  on  the  faying  surfaces  of  the  ends  and  longitudinal 
stiffcDers,  are  strips  of  hessian,  coattxl  with  tar  or  marine  gltie,  t«i 
ensure  a  watertight  joint. 

The  inside  surface  of  the  top,  sides  and  ends,  are  well  coated 
with  tar  or  marine  glue,  and  secured  together  with  brass  or 
galvanised  iron  screws. 

The  outside  is  coated  with  marine  glue  covered  with  hessian, 
and  well  ironed  imtil  the  glue  comes  through  the  fabric.  The 
air- case  is  then  completed  by  a  final  coat  of  marine  glue. 


338  SHIPS'  BOATS 

They  are  fitted  in  the  lifeboats  in  a  similar  way  to  the 
metal  air-cases,  and  the  usual  precautions  taken  to  ensure 
there  is  no  movement  after  being  placed  in  position  behind  the 
clcading. 

The  regulations  issued  by  the  Board  of  Supervising  Inspectors 
in  the  United  States  of  America,  relating  to  buoyancy  air-cases,  are 
of  interest  to  British  boatbuilders,  and  the  following  particulars 
are  taken  from  the  Edition  of  General  Rules,  dated  April  8th 
1918,  viz.  :— 

'*  All  lifeboats  contracted  for  after  September  30th,  1912 
**  shall  have  not  more  than  50  per  cent,  of  the  air-tank  capacity 
"  in  the  ends  of  the  boat,  and  the  remaining  capacity  shall  be 
**  located  in  the  side  tanks. 

"  After  June  20th  1912,  the  air- tanks  of  all  lifeboats  shall  be 
*'  entirely  independent  of  the  hull  or  other  construction,  and  shall 
''  be  of  suitable  non-corrosive  material  and  of  a  capacity  of  not  less 
"  than  1*5  cubic  feet  for  each  person  allowed  in  metallic  boats, 
"  and  not  less  than  1  cubic  foot  for  each  person  allowed  in 
"  wooden  boats.  Such  air-tanks  shall  be  firmly  and  securely 
''  fastened  in  tlic  hull,  and  in  such  a  manner  as  will  allow  them  to 
**  be  temporarily  removed,  and  in  no  case  shall  the  tank  be 
"  punctured  or  opened  for  such  fastenings. 

"  The  tops  of  such  tanks  shall  be  thoroughly  protected  by  a 
**  grating  or  platform,  or  by  the  thwarts  or  seats.  Such  air-tanks  of 
"  G  cubic  feet  or  less  shall  be  constnicted  of  material  of  a  thickness 
*'  not  le.ss  than  No.  22  B.W.G. ;  from  6  cubic  feet  to  and  including 
**  15  cubic  feet,  of  a  thickness  not  less  than  No.  20  B.W.G. ;  and 
"  all  air-tanks  of  more  than  15  cubic  feet  capacity  shall  be  of  a 
**  thickness  not  less  than  No.  18  B.W.G. 

*'  All  joints  of  air-tanks  shall  be  properly  double  riveted 
**  and  tightly  caulked  or  securely  hook-jointed  and  efiiciently 
"  soldered,  or  properly  and  securely  welded,  and  such  air-tanks 
**  shall  be  located  in  such  a  manner  as  will  permit  the  lifeboat 
''to  be  on  as  near  an  even  keel  as  possible  when  flooded  with 
••  water. 

**  The  cubical  contents  of  air  space  of  air-tank  shall  be  stamped 
*•  on  the  tank  where  same  can  be  seen  when  air-tank  is  placed  in 
the  boat. 

Ml  air-tanks  shall  be  fitted  with  a  connection  of  one  half- 
'*  inch  outside  diameter,  for  testing  purposes. 

"  Bt'fore  any  lifeboat  is  passed  and  accepted,  the  air-tanks 
*•  thereof  shall  be  tested  in  the  presence  of  an  inspector  of  this 
''  service,  by  an  air  pressure  of  not  more  than  1  lb.  to  the  sqiLare 


I 


CONSTRUCTION  OF  BUOYANCY  AIR-CASEK     339 

"  iiich.  At  eacli  aiibsoquent  annual  inspection,  ot  oftener  if  in 
"  the  opinion  o£  the  inspectora  it  ia  necessary  or  desirable,  the 
"  inspectors  shall  satbfy  themselves  that  the  tanks  are  ot  good 
"  condition,  but  pressure  need  not  be  applied  imlesa  the  inspectors 
"  are  in  doubt  regarding  the  efficiency  of  the  tanks. 

"  This  doea  not  take  from  the  inspectors  the  right  and 
"  authority  to  satisfy  themselves  at  any  time,  either  by  examina- 
"  tion  or  pressure,  as  to  the  condition  of  the  tanks." 


'ARIOUS     OLASSSS     OF 

Wooden  Lifeboats  of  Class  Ia. — The  buoyancy  of  a  boat  of 
this  type  is  provided  by  watertight  air^caaes,  the  total  volume  of 
which  is  to  be  at  least  equal  to  ten  percent,  of  the  cvJ»c  capacity 
of  the  boat. 

Wooden  Lifeboats  of  Class  Ib. — The  itU^Tuil  buoyancy  of  a 
boat  of  this  type  is  provided  by  watertight  air-cases,  the  total 
volume  of  which  is  to  be  at  least  equal  to  TJ  per  cent,  of  the  cubic 
capacity  of  the  boat. 

K  the  external  buoyancy  is  of  cork,  its  volume  id  not  to  be 
less  than  thirty-three  thousandths  of  the  cubic  capacity  of  the 
boat. 

Open  Lifeboats  of  Class  IIa. — ^A  boat  of  this  type  is  fitted  with 
watertight  air-casea  for  internal  buoyancy,  and  usually  with  sohd 
cork  [or  external  buoyancy,  they  must  be  at  least  equal  to  the 
following  amounts : — 


Air-cases 

External  buoyancy  (if  of  cork)  . 


1-5  cub.  ft. 


for  each  person  which  the  boat  ia  able  to  accommodate. 

Open     Lifeboats    of     Hodifled     Class     IIa. — The     dif!erence 

between  thia  type  of  boat  and  the  Class  IIa  roainly  consists  in 
^^  diapcnsing  with  the  outside  buoyancy  and  increasing  the  internal 
^^  buoyancy,  made  up  by  metal  air-cases,  the  volume  of  which  is 
^H  at  least  equal  to  17  cub.  ft.  for  each  person  which  the  boat  is 
^H   able  to  accommodate. 

^1  Steel  Lifeboats  of  Classes  Ia  and  Is.— In  the  case  of  a  metal 
^H  boat  an  addition  should  be  made  to  the  cubit;  capacity  of  the 
^H  internal  buoyancy,  by  increasing  the  volume  of  the  watertight 
^B  air-cases,  so  as  to  give  buoyancy  equal  to  that  of  the  wooden 
^H  boat. 


340  SfflPS'  BOATS 

The  additional  volume  of  air-cases  required  for  metal  lifeboats 
is  obtained  from  the  following  formula : — 

V=.KW 

V  =>  additional  capacity  in  cubic  feet. 

W  =:  the  weijL^ht  of  the  metal  hull  in  cwts.,  exclusive  of  fittings, 

equipment,  and  air-cases. 
K  =  175  when  the  mean  weight  of  the  air-cases  is  7  lbs.  or 

less  per  cub.  ft.  of  capacity. 
K  =:  2  when  the  mean  weight  of  the  air-cases  is  14  lbs.  per 

cub.  ft. 

When  tlie  wei«^ht  of  the  air-cases  is  between  7  and  14  lbs.  per 
cub.  ft.  capacity,  the  value  of  K  is  found  by  interpolation. 

Wooden  Motor  Lifeboats,  Classes  Ia  or  Ib. — In  fixing  the 
volume  of  the  internal  buovancv,  and,  where  fitted,  the  external 
buoyancy,  regard  must  be  paid  to  the  difference  between  the 
weight  of  the  motor  and  its  accessories,  and  the  weight  of 
the  additional  persons  which  the  boat  could  accommodate,  if 
the  motor  and  its  accessories  were  removed. 

The  Life-saving  Appliances  Rules  are  somewhat  vague  to  the 
mind  of  the  boatbuilder  as  to  what  is  actually  requied.  The 
requirements  can  be  made  explicit  by  an  example — 

Take  a  wooden  motor  boat  of  the  following  dimensions  : — 

220'X70'X2'9". 
Capacity  of  boat  measured  by  Simpson's  Rule  =  256  cub.  ft. 

=>  25  persons. 
( 'apacity  coefficient  of  form  =  '6. 
Diiuensious  of  motor  and  suitable  space  for  working 

■•^  i-ry  X  3-5'  X  2-9'  =-  45-68  cub.  ft. 
which  therefore  displaces  4  persons  (45'68  -r- 10). 

(a)  Internal  buoyancy  required  by  boat  capacity  for  a  Class  I  a 
lifeboat  =^  -,'o "  ^  25*5  cub.  ft. 

(b)  Internal  buoyancy  required  for  motor,  etc. — 
Weight  of  motor  and  accessories  estimated  at  7*5  cwts. 
Buoyancy  per  cwt.  (metal)  =  1*75 

7-5  X  1-75  =  1313  cub.  ft. 

(c)  Buoyancy  for  persons  displaced  by  motor,  etc. — 
Weight  of  4  persons  displaced  by  motor  and  gear 

==  4  X  165  lbs.  =  5-9  cwts. 


CONSTRUCTION  .  OF  BUOYANCY  AIR-CASES      341 

Buoyancy  at  1  cub.  ft.  per  person  =  '68  cub.  ft.  per  cwt. 
Therefore,  buoyancy  displaced  =  '68  X  5*94  =>  4  cub.  ft. 

Summary. 

Buoyancy  required  at  (a)      =  25-5   cub.  ft. 

(6)      =13;13      „ 

Total  38-63 

Deduct  buoyancy  displaced  at  (c)      =   4*00 

34-63 


it 
>> 

if 


Total  number  of  persons  given  by  capacity  rule  =  25. 
Number  of  persons  displaced  by  motor,  etc.    =   4. 

If  seating  accommodation  is  provided  for  21  persons,  then  the 
buoyancy  air-cases  must  be  34*63  cub.  ft. 

If  seating  accommodation  is  provided  for  only  17  persons, 
then  the  buoyancy  air-cases  must  be  34-63—4-0  (4  persons  less 
@  1  cub.  ft.  per  person) 

=•  30-63  cub.  ft. 

Note. — If  the  motor  boat  is  constructed  of  steel  then  the 
buoyancy  air-cases  must  be  increased  in  volume  so  as  to  give 
buoyancy  to  the  steel  hull  equal  to  that  of  a  wooden  boat. 


PART  VJl 


SECTION  A.— EQUIPMENT  OF  BOATS 
There  has  been  frequent  complainta  when  inquiries  have  been 
held  in  regard  to  various  casualty  cases,  as  to  the  inefficiency  or 
the  absence  of  some  details  of  the  equipment  in  the  lifeboats. 

The  Life-saving  Appliances  Rules  make  full  provision  for  all 
reasonable  emergencies  which  a  lifeboat  is  hkely  to  encounter 
and  it  largely  depends  upon  the  ship's  officers  as  to  whether  this 
equipment  is  kept  in  satisfactory  condition  and  always  remains 
in  an  accessible  position. 

Adequate  provision  should  be  made  in  the  boats  to  suitably 
stow  the  various  details  of  equipment,  to  enable  them  to  remain 
in  a  serviceable  condition  and  be  protected  from  the  weather. 
A  simple  plan  is  to  build  lockers  into  the  ends  of  the  boat,  having 
portable  platforms  adequately  supported  above  the  keelson,  and 
protected  at  the  front  with  strong  hinged  doors  fitted  with 
suitable  slip  bolts. 

The  statutory  rules  do  not  at  present  demand  the  fitting  of 
these  lockers,  but  the  experience  of  our  sailors  who  were  cut 
adrift  from  their  vessels  during  the  recent  submarine  warfare, 
and  exposed  for  several  days,  and  even  weeks,  in  an  open  boat, 
should  be  sufficient  evidence  of  the  necessity  for  making  the 
provision  referred  to. 

■  "Where  competition  is  keen  among  so  large  a  number  of  boat- 
builders,  it  is  e^ntial  to  stipulate  every  detailed  requirement, 
and  not  to  leave  these  matters  to  the  persuasive  powers  of  the 
surveyor  or  to  the  common  sense  of  the  builder.  The  demands 
should  be  clean  cut  and  definite,  which  will  ensure  satisfaction 
to  all  concerned. 

The  details  of  eqiupment  depend  on  the  classification  of  the 
vejisel.  That  is  to  say,  the  trade  of  the  vessel  has  a  direct  bearing 
on  the  requirements  ft)r  providing  the  boats  with  those  essentials 
which  will  enable  the  crew  and  passengers,  in  case  of  disaster, 
to  be  succoured  until  the  arrival  of  assistance  ;  it  would,  therefore. 


EQUIPMENT  OF  BOATS  343 

be  advantageous  to  give  in  detail  tlie  full  ecjuipiuent  which  is 
required  by  the  Life-saving  Appliances  Rules,  for  the  various 
clasacs  of  vessels. 

For  a  dettcription  of  the  various  classes  of  vessels,  reference 
should  be  made  to  Section  A  of  Part  II.,  as  it  seems  unueceasary 
to  repeat  the  explanation. 


EQOIPHBNT    OF  BOATS    FOR  FOREIGN-GOING  VESSELS. 

Classes  I.,  II.,  III.,  and  IV. 

Every  boat  which  forms  part  of  the  statutory  equipment  of  a 
vessel  should  be  supplied  with  the  following  details,  viz. : — 

1.  A  full  single-banked  complement  of  oara,  two  spare  oars, 
and  a  steering  oar;     {See  Table  XXII,) 

2.  Two  plugs  for  each  plug  hole,  attached  to  the  boat 
with  lanyards  or  chains.  These  are  not  required  where  proper 
automatic  valves  are  fitted. 

3.  One  set  and  a  half  of  thole  pins  or  cmtches  attached  to  the 
boat  by  sound  lanyards, 

i.  A  sea  anchor. 

5.  A  balpr  with  lanyard  attached,  which  should  be  of  sufficient 
size,  and  made  suitable  for  baling,  the  upper  diameter  not  being 
less  than  8  in. 

6.  A  galvanised  iron  bucket  to  hold  2  gallons,  with  lanyard 
attached. 

7.  A  painter,  not  less  than  20  fathoms  in  length. 

8.  A  nidder  and  tiller,  or  yoke  and  yoke  lines.  The  rudder 
and  tiller  t^i  have  lanyards  of  sufficient  length  to  enable  them  to  be 
securely  attached  to  the  boat. 

9.  A  boat  hook  of  convenient  length,  and  strong  enough  for  the 
purpose  requited. 

10.  A  vessel  capable  of  holding  one  quart  of  fresh  water  for 
each  person  that  the  boat  is  deemed  fit  to  carry.  This  vessel 
must  be  kept  filled,  and  provided  with  a  suitable  dipper  attached 
to  a  lanyard.  Two  galvanised  iron  tanks  or  breakers  arc  required 
in  the  large  boats,  to  hold  the  specified  quantity  of  water,  the 

I  smaller  size  being  more  convenient  for  sttiwage  and  handling 
and  less  likely  to  be  damaged. 
11.  Two  hatchets,  attached  to  the  boat  by  a  lanyard  and 
stowed  one  at  each  end  of  the  boat,  ready  for  cutting  the  falls 
or  painter  if  necessary. 
12.  A  life-line  securely  becketted   round  the  outside  of  the 


344  SfflPS'  BOATS 

boat,  secured  to  life-rings  clenched  to  the  timbers  not  more  than 
2  ft.  apart,  having  loops  of  sufficient  depth  that  will  always  remain 
a  few  inches  above  the  water-line. 

13.  An  efficient  lantern  trimmed  with  oil  in  its  receiver, 
sufficient  to  bum  eight  hours,  and  capable  of  burning  in  a  strong 
wind.  This  should  be  of  brass  or  copper  frame,  and  of  a  size 
that  will  conveniently  fit  in  the  galvanised  bucket  referred  to 
in  item  0. 

14.  A  mast  or  masts,  not  more  than  two-thirds  the  length  of 
the  boat,  with  at  least  one  good  sail  and  proper  gear  for  each.' 
(See  Table  XIV.  and  Section  B,  Part  VII.) 

This  rc(iuirement  does  not  apply  to  an  approved  motor  boat. 

15.  A  licjuid  compass. 

1().  An  airtight  case,  ccmtainifig  two  pounds  of  biscuits  for 
each  person  for  whom  the  boat  is  approved. 

17.  One  galhm  of  vegetable  or  animal  oil. 

18.  A  vessel  of  api)r()ved  pattern  for  distributing  the  oil  on  the 
water  in  rough  weatlier.  This  vessel  must  be  capable  of  being 
attached  to  the  sea-anchor. 

19.  One  dozen  self-igniting  red  lights  in  a  watertight  tin. 

20.  A  box  of  suitable  matches  in  a  watertight  tin. 

The  above  details  are  to  be  kept  so  as  to  be  at  all  times  fit 
and  n^adv  for  use. 


EQUIPMENT  OF   BOATS    FOR  HOME   TRADE    VESSELS. 

Classes  I.,  II.,  III.,  IV.  and  V. 

Every  boat  which  forms  part  of  the  statutory  equipment  of  a 
ve^jsel  must  be  siij)j)lie(l  with  the  details  as  shown  in  the  foregoing 
list  for  forcign-uoiii.t:  v(\ss(»ls,  with  exception  of  items  14  and  16. 

EQUIPMENT   OF   BOATS    FOR    HOME  TRADE    VESSELS. 

Classes  VI.,  VII.,  X.,  and  XI. 

Full  details  to  be,  supplied  as  shown  for  foreign-going 
vessels,  excei)t  items  14,  15.  1(),  17,  18,  19  and  20. 

EQUIPMENT  OF   BOATS  FOR   HOME   TRADE  VESSELS. 

Classes  VIII.  and  XII. 

Full   details    to   be    supplied    as    shown    for    foreign-going 
vessels,  except  items  4,  G,  10,  14,  15,  IG,  17,  18,  19  and  20. 


EQUIPMENT  OF  BOATS 


EQUIPMENT    OF   BOATS    FOB    HOME  TRADE  VESSELS. 
Class  IX. 

Full  details  to  be  supplied  as  shown  for  foreign-going 
vessels  except  items  4,  6, 10,  IS,  14, 15, 16, 17,  18,  19,  and  20. 

The  full  equipment  of  boats  for  vesaela  of  Class  IX.  would 
therefore  be — 

-  [a]  A  full  single-banked  complement  of  oara,  two  spare  oars, 
and  a  steering  oar. 

(fe)  Two  plugs  for  each  plughole,  and  attached  to  the  boat  by 
lanyards  or  chains. 

(c)  One  set  and  a.  half  of  thole  pina  or  cnitches. 

(d)  A  baler  with  lanyard  attached. 

(e)  A  painter  of  sufficient  length. 

(/)  A  rudder  and  tiller,  or  yoke  and  yoke  Unes, 

ig)  A  boat  hook. 

(h)  Two  hatchets,  with  lanyard  attached.     (See  note  below.) 

(i)  With  a  Lne  securely  becketted  around  the  outside  of  the 
boat. 

Note. — Where  boats  of  vessels,  Classes  VIII.,  IX.  and  XII. 
are  put  into  the  water  by  hand,  and  not  by  means  of  davits  or 
other  mechanical  appliances,  they  need  not  be  provided  with 
hatchets  (item  11). 

Class  III.  boats,  which  form  part  of  the  statutory  equipment 
of  a  vessel,  are  provided  with  the  same  details  as  a  lifeboat ;  the 
only  difference  between  this  type  of  boat  and  the  lifeboat  of 
Claas  Ia  is  that  the  former  is  not  fitted  with  buoyancy  air-cases. 

The  Board  of  Trade  may  exempt  from  the  requirement  to 
carry  masts,  sails,  and  compasses,  a  proportion  of  the  boats  of 
ships  which  carry  passengers  in  the  North  Atlantic  and  are 
equipped  with  wireless  telegraphy. 

To  provide  a  quick  and  ready  means  of  identifj-ing  the  boats 
which  are  fully  equipped  on  such  a  vessel,  it  is  usual  to  paint  a 
broad  red  band,  at  least  3  in.  in  breadth,  around  the  outside  of 
the  boat  under  the  rudder. 

The  whole  of  the  equipment  provided  must  be  of  good  quality 
and  efficient  for  the  purpose  intended. 

Unless  periodica!  inspection  is  made,  and  the  lockers  kept 
free  from  dirt  and  water,  the  details  of  equipment  will  very 
quickly  deteriorate,  it  is  therefore  the  duty  of  the  ship's  officers  to 
see  that  all  the  gear  is  in  proper  condition  and  stowed  in  all  the 
boats,  and  carefully  inspected  at  each  periodical  boat  drill. 


346  SHIPS'  BOATS 

Tabic  XXII.  on  p.  347,  gives  a  detailed  statement  showing 
the  length  of  oars  required  for  boats  of  certain  length.  The  oars 
should  be  of  straight-grained  ash ;  in  good  class  boats  the 
blades  are  copper  tipped  and  leather  bound  in  way  of  crutches 
or  thole  pins.  The  lengths  vary  to  suit  the  particular  size  of 
boat,  the  position  of  the  thwart,  and  the  height  of  the  gunwale 
above  water. 

The  position  of  the  crutches  should  be  so  arranged  that  the 
boat  can  be  pulled  with  a  greater  number  of  oars  on  one  side,  to 
suit  the  conditions  of  wind  or  stress  of  weather.  This  is  the 
reason  why  the  crutch  plates  should  be  double-banked  in  the 
smaller  boats. 

In  this  connection,  it  facilitates  easy  removal,  if  the  crutches 
are  secured  to  the  boat  by  lanyards  instead  of  chain,  in  order  to 
allow  them  to  be  placed  in  the  most  suitable  positions  for  rowing. 

The  limit  in  length  for  a  steering  oar  is  16  ft. ;  it  is  painted  a 
distinctive  colour  so  as  to  be  easily  recognised,  and  is  usually 
about  1  ft.  greater  in  length  than  the  longest  rowing  oar  supplied 
to  the  boat.  The  blade  should  be  wider  than  that  of  the  ordinary 
pulling  oar. 

The  simplest,  most  efficient,  and  one  of  the  oldest  methods  of 
holding  the  steering  oar  is  by  fitting  a  wire  grommet  served  over 
with  marlin  stuff  or  spun  yam.  This  grommet  is  seized  behind 
the  ring  bolt  and  a  good  security  made.  The  length  of  the 
grommet  should  be  such  that  the  blade  of  the  steering  oar  can 
easily  be  inserted  and  the  oar  used  on  either  side  of  the  stempost. 
To  protect  the  capping  of  the  gimwale,  rubbing  pieces  well 
rounded,  should  be  fitted  on  each  side  of  the  stempost  for  about 
15  in.  from  the  sternpost  head,  secured  by  screws  to  the  gimwale. 
It  is  mucli  easier  to  renew  the  loibbing  pieces  than  repair  the 
upper  strake  or  gunwale.  Details  of  this  method  is  shown  in 
Fig.  103. 

In  a  square-sterned  boat,  a  rowlock  is  usually  cut  in  the 
transom  for  the  purpose  of  sculling.  The  steering  grommet  is 
seized  behind  the  ring  bolt  in  the  usual  way,  the  grommet  and 
rowlock  combined  forming  an  efficient  means  for  supporting  the 
steering  oar. 

The  sea  anchor  nuist  be  ccmstructed  of  good  quality  canvas. 
Keen  competition  among  ship  chandlers,  without  a  universal 
specification  or  definite  standard  to  work  to,  has  been  responsible 
for  many  inferior  fittings  being  supphed  for  the  boat's  equipment, 
which  includes  the  sea  anchor,  the  purpose  of  which  is  to  allow 
the  boat  to  ride  stcadilv  in  a  seaway.     The  sea  anchor  acts  as  a 


EQUIPMENT  OF  BOATS 


347 


drag,  and  is  used  in  association  with  the  oil  distributor,  which  is 
supposed  to  break  down  the  roughness  of  the  wave  surface. 


TABLE   XXII. 

Pabttoulars  of  Thwarts,  Cbutohes,  and  Oabs,  fob  Boats  of  Classes  Ia, 

Ib  and  III. 


Length  of 

boat  in 

feet. 


16 


17  &  18 
19&20 


21,  22. 
&23 

24 


25  &  26 


27 


28 


29  &  30 


Number 

of 
thwartfl. 


6 
6 
6 


Number  of 
crutch  plates. 


Single- bank      I 

No.  I  Thwart. 

Double- bank 

2nd  and  3rd 

Thwarts. 

Total  5. 

Ditto. 


Single- bank 

No.  1  Thwart. 

Donble-bank 

elsewhere. 

Total  7. 

Ditto. 


Ditto. 


Ditto. 
Total  9. 

Ditto. 


Ditto. 


Double-bank 

Five  Thwarts. 

Total  10. 


Total  No. 
of  crutches, 
including 
spare. 


6 


0 


6 


6 
6 
6 
6 
8 
8 


Total  No. 
of  rowing 

oars 

including 

spare. 


5 


6 


6 


6 


6 


6 


8 


8 


Length  of  Length  of 

rowing      steering 

oars  in       oar  in 

feet.  feet. 


10 


2  @  10 

3  @  12 

2  @  11 

4  @  12 


2  @  11 
4  @  13 

2  @  12 
4  @  14 

2  @  12 

4  @  14 

2  @  13 

4  @  14 

2  @13 
6  @  14 

2  @  13 
6  @  15 


12 


13 


13 


14 


15 


15 


16 


16 


16 


Fig.  195  A  shows  one  type  of  anchor,  circular  in  section,  not  less 
than  24  in.  in  diameter,  made  up  from  canvas,  well  strengthened 
by  hemp  rope  ;  attached  to  the  sea  anchor  is  a  stout  rope  trailer 
and  tripping  Une,  20  fathoms  in  length.  The  tripping  line  is  used 
to  turn  the  tail  of  the  anchor  towards  the  boat  and  enable  it 


348 


SHIPS'  BOATS 


to  be  drawii  on  board,  The  hoop  aroiind  which  the  coitvas 
secured  should  be  of  substantial  section  and  made  suitable  for  ths 
purpose  intended.  This  pattern  of  anchor  is  an  awkward  shape 
for  stowing  in  the  lockers,  and  very  quickly  deteriorates  when 
lying  at  the  bottom  of  the  boat.  Fig.  195  b  illustrat«s  another 
pattern  which  is  eaeily  rolled  up  and  stowed  away,  but  it  ia 
doubtful  whether  it  possesses  any  advantage  in  actual  use  over 
the  one  previously  deacribed.  It  consists  of  a  piece  of  stout 
canvas  2  ft.  10  in.  square,  with  a  wood  float  3  ft.  3  in.  in  length 
and  3  in.  by  2J  in.  in  section  at  one  end,  and  an  iron  bar  at  the 
other.  The  feature  of  the  latter  is  to  keep  the  canvas  under 
water,  as  in  conjunction  with  the  trailer  and  tripping  Una 
attached  to  the  canvas,  it  makes  a  8coop  and  provides  th« 
necessary  resistance  or  drag. 

The  oil-distributing  apparatus  should  be  capable  of  distributing 
oil  evenly  and  gradually  on  the  surface  of  the  water ;  it  is  usually 
attached  to  the  sea  anchor.  The  common  fitting  supplied  is  an 
ordinary  thin  canvas  bag  with  a  narrow  neidt,  which  is  a  most 
unsatisfactory  and  a  useless  article  for  the  purpose  required.  A 
better  class  of  distributer  is  shown  in  Fig.  196.  It  consists  of  & 
stout  canvas  body  with  a  metal  spigot  securely  attached  to  the 
former,  having  a  screwed  cap  which  can  be  adjusted  to  allow  the 
oil  to  be  distributed  in  suitable  quantity.  Other  patterns  are 
on  the  market,  hut  they  very  rarely  become  a  part  of  the  equip- 
ment, because  the  cheaper  article  appears  to  satisfy  the  present 
requirements. 

The  painter  should  be  not  less  than  20  fathoms  in  length.  It 
is  a  great  advantage  to  have  two  of  these  in  each  boat ;  during 
the  recent  submarine  warfare  it  was  insisted  upon  as  an  essential 
part  of  the  equipment,  one  being  fitted  with  a  strop  and  toggle, 
and  the  end  led  forward  and  kept  belayed  to  a  cleat  or  othei 
suitable  fitting  fixed  on  the  deck  or  bulwark. 

The  purpose  of  this  painter  is  to  allow  the  boat  to  be  lowered ' 
before  the  vessel  has  come  to  rest,  and  to  enable  the  seamen  to 
reheve  the  boat  from  the  falls. 

This  provision  particularly  applies  to  lifeboats  stowed  oa 
the  poop,  or  near  the  after  end  of  the  ship ;  the  cleats  shouldi 
be  so  placed  that  boats  when  lowered  and  freed  from  the  tackle^, 
with  the  ship  light,  can  be  held  by  the  painter  clear  of  the  coiintaE^ 
and  propellers. 

The  remaining,  or  second  painter,  should  be  neatly  coiled 
stowed  in  the  boat,  ready  for  use  if  required  after  launching. 

If  only  one  painter  ia  supplied,  and  it  becomes  ni 


I 
I 


EQUIPMENT  OF  BOATS 


349 


rmpptAfc 

UNE 


-  ELEVATION  - 


■  PLAN- 

Fia.  195  A  and  b. — IX^tails  of  sea 
anchor. 


B 


CANVAS 
2-10  %  2.IO 


IRON    ROD 


MerAL  Af£C/( 


SlS£Y£ 


CAP 


r\  m 


Fio.  196.— -Details  of  oil  distributer. 


SOO  SHIPS'  BOATS 

Ut  cut  tlic  li'iat  aflrift  from  the  veuel  with  the  hatchet,  the  bcwt 
will  li';  li;ft  without  meatu  for  towing  in  case  of  neccBsity,  tinlt<w; 
the  m-ji  unchor  trailer  i^  used  for  the  pnipose. 


'I'lii-  ]iriivisiiiii  i>f  siiiluhli'  rrxsrls  fur  holiliiif)  fresh  tmter  is  of 
niiiMi>l('i'iili]t>  itii|>ni'(itiit't'.  Ilroukocs  or  bairicoeii  are  usually 
uujipliiHl.    'I'wo  in  uuuibev  uro  placed  in  each  boat,  conta' 


EQUIPMENT  OF  BOATS 


351 


total  quantity  of  water  equal  to  an  allowance  of  one  quart  for 
each  person  the  boat  is  certified  to  carry, 

A  gallon  of  distilled  water  weighs  10  lbs.,  ao  that  the  capacity 
of  the  breaker  can  be  checked  by  ite  weight  when  filled. 

New  breakers  should  be  filled  immediately  they  are  euppUed 
to  a  boat,  in  order  that  the  wood  may  absorb  and  become  water- 
tight. They  should  be  neatly  stowed  in  cradles  on  each  side  of 
the  keelson,  clear  of  the  lower  seats,  and  lashed  to  eye-plates  to 
prevent  them  being  lost  overboard.  Fig.  197  d  illustrates  the 
method  of  stowing. 

The  dippers  ate  attached  to  the  breakers  and  weighted  so  as 
to  allow  the  mouth  to  get  below  the  surface  of  the  water.  The 
mateiial  must  be  of  copper  or  zinc,  and  tinned  on  the  inside. 
Tin  dippers  arc  condemned  as  a  source  of  danger,  and  quickly 


Fill.  Vit. — Jli'thod  uf  fitting  two  biscuit  tanks  uoder  one  thwart. 

ruat  when  exposed  to  the  sea  atmosphere.  Particular  care  should 
always  be  taken  to  see  that  the  dippers  will  enter  the  plughole  of 
the  breakers  without  difficulty. 

Gaivani.'^cd  iron  tanks  are  considered  preferable  to  wooden 
breakei-s.  The  fittings  connected  with  them  must  be  of  metal, 
and  not  of  cast  iron,  to  prevent  rusting. 

Biscuit  Cases. — Airtight  metal  tanks  are  fitted  in  the  boat  to 
c()ntain  2  lbs.  of  biacuita  for  each  person  the  boat  is  certified  to 
carry. 

No  single  tank  should  contain  more  than  from  50  to  56  lbs.  of 
biscuits,  so  that  if  a  boat  is  certified  to  carry  29  persons,  two 
separate  tanks  nmst  be  provided. 

In  a  lifeboat  with  five  thwarts,  and  where  the  mast  is  stepped 
on  the  second  thwart,  the  two  biscuit  tanks  can  he  fitted  side  by 
side  under  the  third  thwart,  and  secured  as  shown  in  Fig.  198, 
but  in  lifeboats  fitted  with  si^  thwarte,  the  biscuit  tanks  can  be 


352 


SmPS'  BOATS 


iDastzsted 


m^Mml  U,  Heparate  thwarte,  if  considered 

ViuU'TtinUt  metal  ocrcw  caps,  not  less  f k 
yhmUl  \„.  f.ttwl  U>  the  biscuit  tanks,  which.!!^^  ^  ™  di«neter, 
tr.  B  I..W  a  p.,rw.n  t.,  place  his  arm  inside  faT^  **''?*  «oagh 
(.f  the  tHiikx.  ^"®'  *<>  the  remotttt  con^ 

A  key  or  levc;r  is  suppHed  and  attached  to  tl.»  k_    , 
or  eham,  .,r  .,,,enin«  the  brass  cap,  unless  Sel-^T*-  ^^  ^^^ 
with  the  lever  attached.  ™®  tatter  is  so  fonned 

The  „„iteriul  Hhould  be  of  galvanised  sheet  im      ^ 

£^»5*rr  "'  anrabl^  and 


mr. 

TANK 


I 


-  ELEVATION  ^ 


Km.  I!M».     .MrtlHMl  of  jiiiin^r  Hinglc  biscuit  tank  under  thwart 

of  Htron;',  Mcantlin«;.     TIk*  usual  size  of  sheet  is  6  ft  X  3  ft    r  ri  ^-u 
Miirknrss  viiiirs  from  20  to  22  W.G.  *  *'       ^  ^^® 

Kor  Mic  purpose  of  socuriiijr  a  satisfactory  cubic  capacit 
fiirlor,  to  pinihlc  a  lank  to  ho  of  sufTicient  volume  to  contam  th^ 
nM|uinMl  amount  of  l>is('uit.s,  the  writer  secured  typical  sizes     f 
slii|)s'  hiscuits  ami  foinul  the  volume  taken  up  by  one  poiind 
in  IIm'  followin;;  manntM* :--  ' 

12  in  numlxM-,  hiscuit^s  ((/  \\V'  diameter  =  1  lb. 

Dimousions  for  1  Ih.      lU"  X  3.1"  X  GJ"  =  76-5  cub.  in. 

8  in  numher,  l)isruits  ((/  '1|"  diamet^^r  =  IJ  lbs. 

Dimensions  for  \\  lhs.r_-li"x  41"  x4i"=76-7  cub.  in. 

7(r7x  1^>^  722  cub.  in.  for  lib. 
17 


EQUIPMENT  OF  BOATS 


353 


^        The  basis  for  the  eapacitv  of  a  biscuit  tank  is  therefore  taken 
'       as  100  cub.  in.  =  1  lb. ;  1  cub.  ft.  (1728  cub,  in.)  =  17^  lbs. 

It  then  becomes  an  easy  matter  to  make  a  tank  that  will  be 
larfje  enough  to  take  the  required  amount  of  biacuita,  provided 
wc  know  tliB  number  of  persons  the  boat  is  supposed  to  carry, 
and  the  depth  available  between  the  top  of  the  keelson  and  the 
underside  of  the  thwart. 

The  following  iuiorraation  will,  therefore,  be  useful  in  pro- 
vidinj;  biscuit  tanks  for  lifeboats  of  Classes  Ia  and  In.  and  boats 
of  Class  III. 

TABLE   XX]  11. 

DlBTiJfCB  BFTWRRN  BoTTOH  OF  ThWAHT  AND  ToP  OI>  KlELSOS,  IH  LirEBOATS 

or  Classes  Ia  and  Ib,  ahd  Boats  or  Ciabs  III.,  ron  the  Acoohuooa- 
■nos  at  BiscitiT  Tanks. 


DlD,eiwloii^  of  l«)iit. 

No.  01 
l«r«uB. 

So.  o(  Ibg. 

ol  bbcnlta. 

Oeptli  kvailiMe 
lor  blwult 

Single  biMuit  tank  in  each  boat  :— 
l6-0x575'x2-3' 
18-0'xfi-2fl'x24' 
20-0' X  0*78' X  26' 
22-0-x7-2a'xa-76' 

11 
ai 

2fi 

24 
32 
42 

52 

1'2* 

i'3r 

1-6- 

Two  bisoDit  tanka  in  esch  boat  :— 
2*0'y7G'x30' 
26fl'x8-0'x3-25' 
280' X  8-5' X  36' 

32 
40 

60 

04 
80 
100 

■:-i; 

Three  biioait  tanks  in  each  boat  :— 
3O0'x90'x3-75' 

00 

120 

2   3J- 

Compass. — The  compass  must  be  in  accordance  with  handbill 
No.  377,  issued  bv  the  Board  of  Trade  m  July,  1916.  The  dry 
card  compass  has  been  discarded  as  a  useless  piece  of  equipment. 
Proper  liquid  compasses  must  now  be  provided  and  fitted  in  a 
brass  binnacle,  or  in  a  suitable  wooden  box.  The  former  are 
much  t*i  be  preferred. 

Efficient  accommodation  should  be  made  for  the  reception  of 
the  compass,  that  it  may  be  protected  from  the  weather  and  be 
in  such  a  position  from  which  the  coxswain  can  steer  the  boat 
without  difficulty.  The  usual  plan  is  to  secure  a  small  box  under 
the  after  thwart  immediately  in  front  of  the  stem-sheets,  with 
a  hinged  front.  The  base  of  the  binnacle  must  be  secured  to  a 
wooden  slide  to   aUow  the  compass  to  be  withdrawn  for  the 

2  A 


354  SfflPS'  BOATS 

purpose   of   trirnming    the  lamp.      Such   an   anangemeiit    is 
illustrated  in  Fig.  197  E. 

The  internal  size  of  the  compass  box  will  varr  accoiding  to 
the  pattern  of  compass,  but  the  following  dimensions  will  usually 
accommodate  most  of  the  designs  : — 

10  in.  fore  and  aft,  by  14  in.  depth,  by  13  in.  athwartship. 

Ridge  Spars  are  usually  fitted  to  each  boat  of  Classes  Ia,  Ib,  and 
III.,  resting  on  the  stem  and  stempost  heads,  supported  by  an 
upright  from  the  keelson  at  the  centre,  and  two  struts  from  the 
gunwale.  The  purpose  of  the  strut  is  to  take  the  canvas  or 
portable  wooden  covers  which  protect  the  interior  of  the  boats 
from  the  weather. 

The  common  practice  is  to  fit  the  canvas  cover  in  one  piece, 
secured  with  lashings  through  eyelets  to  solid  brass  knobs  fixed 
to  the  imderside  of  the  rubbers. 

It  has  often  been  suggested  to  the  writer  by  ships'  officers, 
that  the  canvas  cover  could  be  lapped  and  laced  at  the  centre, 
and  so  arranged  that  when  the  boat  was  lowered  into  the  water 
the  cover  would  be  retained,  and  secured  by  a  lashing  below  the 
gunwale,  so  as  to  give  the  proper  freedom  for  the  manipulation 
of  the  oars. 

This  scheme  would  allow  the  use  of  the  canvas  cover  as  a 
protection  to  the  passengers  using  the  side  seats,  and  judging  from 
the  experience  of  those  who  were  unfortunate  enough  to  spend 
several  nights  at  sea  in  an  open  boat,  as  a  result  of  their  vessel 
being  torpedoed  at  sea  during  the  recent  war,  the  suggestion  is 
worth  considering. 

Hand  Pump, — Every  boat  above  22  ft.  in  length  could,  with 
advantage,  be  fitted  with  a  small  pump  for  quickly  clearing  the 
bil^ci  of  water.  The  use  of  one  small  bailer  has  very  httle  effect 
in  keeping  down  large  volumes  of  water  coming  over  the  side 
(luring  stress  of  weather. 

Whore  vcHsels  entered  the  war  zone,  the  United  States  Steam- 
boat  Inspection  Service  insisted  on  boats  being  fitted  with  a 
han(l-])uinp,  having  a  plunger  of  not  less  than  2  in.  in  diameter,  and 
a  discharge  pipe  of  sufficient  length  to  reach  clear  of  the  boat's 
sido. 

General  Ite^narks, — After  reading  through  this  section  on  the 
subject  of  equipment,  one  will  naturally  come  to  the  conclusion 
that  a  lifeboat  has  a  considerable  portion  of  its  capacity  taken  up 
with  essential  details.  This  fact  should  be  carefully  considered 
when  the  number  of  persons  are  being  allotted  to  a  particular 
boat. 


EQUIPMENT  OF  BOATS  355 

Some  readers  perhaps  Lave  seen  the  mffenioua  arrangement 
placed  in  lifeboats,  where  a  metal  tank  is  fitted  under  the  after 
thwart  inunediatety  in  front  of  the  stem-sheets,  which  is  a 
self-contained  store  in  miniature  proportions,  divided  into  three 
sections,  an  oil  tank  on  one  side,  and  a  cupboard  on  the  other. 
In  the  centre  is  an  oil  stove  connected  to  tlie  oil  tank.  Carried 
in  the  cupboard  are,  condensed  milk,  meat  juice,  brandy,  a  kettle, 
and  other  apparatus.  Every  convenience  is  thus  provided  for 
making  hot  drinks. 

This  provision  is  worthy  of  consideration,  when  passengers 
ai'u  often  taken  unwell,  or  wounded  persons  are  being  carried  on 
boaid. 

To  provide  contact  between  one  boat  and  another,  a  helio- 
graph for  signallinf5  by  day,  an  electric  torch  for  use  at  night, 
and  a  box  containing  medical  comforts,  are  very  necessary  portions 
foi  inclusion  in  the  equipment,  but  up  to  the  present  date  the 
regulations  do  not  require  these  fittings  to  be  supplied, 

In  addition  to  the  statutory  requirements  of  the  British  Board 
of  Trade,  the  United  States  Steamboat  Inspection  Service  ask 
for  a  canvas  bag  to  be  carried,  containing  sailmaker's  palm  and 
needles,  sail  twine,  marline  and  marline  spike.  The  food,  or 
provisions  required  to  be  carried  in  lifeboats,  may  be  hard  bread 
or  the  "  United  States  Array  emergency  ration."  Food  which 
produces  unusual  or  immoderate  thirst,  such  as  corned  beet,  salt 
fish,  etc.,  is  not  allowed  imder  any  circumstances,  as  lifeboat 
provisions, 

When  hard  bread  only  is  carried  in  the  lifeboat,  there  must  be 
provided,  in  addition  thereto,  at  least  ten  United  States  Army 
Emergency  Rations.  The  latter  is  prepared  in  accordance  vntii 
the  following  formula  :  45'45  per  cent,  chocolate  liquor,  7'27  per 
cent,  nucleo-casin,  7'27  per  cent,  malted  milk,  14o5  per  cent, 
^g  albumen,  2182  per  cent,  powdered  cane  sugar,  and  364  per 
cent,  cocoa  butter.  Each  ration  weighs  8  ozs.  net,  and  is  put 
up  in  three  cakes  of  equal  size.  Each  cake  is  wrapped  in  tinfoil, 
and  all  three  enclosed  in  a  hermetically-seated,  round-cornered 
tin,  with  key-tipening  attachment.  The  formula  thus  described 
is  printed  on  the  container  together  with  the  name  and  address 
of  the  manufacturer. 

Dimemmis  of  each  boat  must  be  plainly  cut  in  on  the  stem  or 
the  upper  strake ;  the  former  is  considered  preferable.  The  size 
of  the  figures  being  at  least  \  in.  in  depth.  The  dimensions 
required  are  the  length,  breadth,  depth,  and  the  number  of 
persons  the  boat   is   certified  to   carry,  and  these  must  be  so 


356 


SmPS'  BOATS 


CA^y^s  co^r^ 


placed  as  to  look  inboard.      The  number  of  persons  is  also  cut 
in  on  the  opposite  side  of  stem. 

Each  boat  must  be  distinctly  niunbered  in  figures  about 
2^  to  3  in.  in  depth.  The  usual  procedure  is  to  paint  tibese 
numbers  in  clear  type  to  enable  the  boat  to  be  readily  identified. 
Starboard  boats  are  given  odd  numbers,  and  those  on  the 
port  side  are  marked  with  even  numbers.  The  foremost  boats 
are,  therefore,  numbered  one  and  two  respectively. 

The  British  Board  of  Trade  issue  a  Life-saving  Appliance 
Certificate  (S.  123),  on  which  is  indicated  the  position  and  number 

of  the  whole  of  ^e  boats  which  form 
part  of  the  statutory  equipment  of 
the  vessel,  it  is  an  advants^e  to  the 
surveyor  if  the  identification  number, 
which  is  placed  by  the  boatbuilder  on 
the  keel  immediately  it  is  laid,  is  also 
inserted  on  the  certificate,  together 
with  the  date  of  construction,  and 
the  name  of  the  boatbuilder.  This 
information  enables  the  boat  to  be 
traced,  and  forms  a  guide  to  the  in- 
spector when  making  a  p^odical 
survey.  Fig.  200  indicates  how  the 
dimensions  are  placed  on  the  stem  of 
a  boat  which  is  situated  on  the  port 
side  forward,  the  dimensions,  there- 
fore, appearing  on  the  starboard  side 
of  the  boat. 

The  measurement  of  the  capacity 
of  a  lifeboat  has  to  be  carefully  con- 
sidered with  reference  to  the  amount 
of  equipment  which  has  to  be  stowed. 
It  is  useless  to  designate  a  boat  as  being  able  to  accommodate 
a  number  of  persons,  given  by  the  approved  factor  or  irnit  of 
capacity,  without  adjusting  the  seating  arrangements  in  con- 
jimction  with  the  various  details  of  equipment.  This  difficulty 
particularly  applies  to  the  smaller  boats. 

As  a  general  rule,  sufficient  care  is  not  exercised  by  the  ship- 
builder to  place  the  gear  in  its  proper  stowing  position,  at  the  final 
inspection  of  the  life-saving^appliances,  immediately  before  the 
vessel  is  delivered  over  to  the  shipowners,  with  the  inevitable 
consequence  that  when  the  boat-s  are  required  on  service,  various 
details  are  missing. 


Fig.  200. 


SECTION   B.^AILS 

RegulatioiiB  alfectlng  Sails. — Boats  which  form  part  of  the 
statutory  e<jiiipment  of  all  classes  of  foreign-goii^  veaaela,  must 
be  provided  with  a  maat  or  masto,  and  at  least  one  good  sail,  and 
proper  gear  for  each. 

This  provision  dues  not  apply  to  an  approved  motor  boat,  or 
to  boats  whieh  are  carried  on  ships  solely  enjiaged  in  the  Home 
Trade. 

In  a  ship  which  carries  passengers  in  the  North  Atlantic,  and 
is  eqiiipped  with  wireless  telej^raphy,  masta  and  aaiU  need  only 
be  provided  in  four  of  the  boats,  but  these  boats  must  be  marked 
so  as  to  distinguisb  them  from  other  boats,  by  means  of  a  red 
band  3  in.  wide,  painted  round  the  outside  of  the  boat 
immediately  below  the  sheer  strake. 

Mast«  must  not  be  more  than  two-thirds  the  length  of  the  boat, 
and  the  sails  should  be  of  j;ood  quality  duck  of  suitable  size,  e.g. 
a  28-ft.  boat  should  have  not  less  than  150  sq.  ft.  of  sail  area, 
other  boats  having  areas  of  similar  proportions. 

Each  sail  should  be  fitted  for  reefing. 

The  boats  must  have  sufficient  stability,  when  in  their  fully 
loaded  condition,  to  enable  them  to  cany  a  aufiicient  spread  of 
sail  in  a  fresh  breeze. 

Propelling  Force  of  Wind. — The  force  of  wind  which  is  exerted 
on  the  sails  of  a  boat  in  order  to  pr6pel  her  forward,  is  not  wholly 
effective  in  moviii[;  her  in  the  same  direction  as  the  keel,  except 
when  the  wind  is  blowing  immediately  behind  the  boat. 

When  sailing  a  boat  to  windward,  the  wind  force  isdirected  on 
the  sails  in  an  oblique  direction.  One  portion  of  that  force  drives 
the  boat  ahead,  and  another  drives  it  to  leeward.  What  we  have 
to  discover  is  the  percentage  of  the  wind  force  which  is  effective 
ill  propelling  the  boat  forward. 

The  explanation  can  be  made  clearer  by  graphically  setting 
t'ut  the  forces,  as  indicated  in  Fig.  201. 

Assume  KK  to  be  the  centre-line  of  boat  and  representing 
the  keel. 

Make  PS  to  show  the  direction  and  force  of  the  wind. 

Resolve  this  force  into  two  components  by  the  application 
of  the  principle  of  the  parallelogram  of  forces,  and  we  then  have 
one  component  NS  or  PC  acting  along  the  surface  of  the  sail 
which  produces  no  effective  forward  motion  to  the  boat.  The 
iither  component  OS  or  PN  is  acting  at  right  angles  to  the  plane 


x> 


.SHIPS    BOATS 


AwriiU'j:  of  tii#;  -ail.    k»5-iilv»>  th*:  f'/rc*  PX  ini»>  rwo  oj 

an/J  w«:  j^ii'Mtf:  x}i('.  htrf*:  PK.  which  U  th<?  m<A£c:r^  »>t  liie  fff^tttm 

f/^iw'rr  /irivinir  th^:  ho;^t  <iheafi.  the  lin<^  ot  Acti<^  bian;Z  pArallei 

Th'r  ot.h#:r  com[>*irient  KX  U  the  measure  of  the  fore??  vhidi  is 
in  op'jration  t'-f»rliri'^'  t/i  driv*^  the  hK>at  to  leeward,  i-if.  moving  the 
^fff(tt  'inU'WfiVA  awav  from  the  wind. 

Th'r  iin/J^rrwat^ir  form  of  the  bf>at.  the  depth  of  the  keel,  and 
tJi'r  jfffMtlion  of  fhe  Hfidn,  all  have  a  direct  influence  in  ci>xmteraetin2 
y\\t'.  t'tttul  of  th<'  forr<;  driviri;:  the  hK>at  to  leeward. 

'{]}*'  Tf"\i*.UiU('ii  oi  the  h-ninh  and  lon^ritudinal  shape  of  the  boat 
to  \n'.  driv^Ti  in  ihf.  dir^frtion  RX  is  comparatively  greater  than 
till-  ft'M'Jiuiff.  ofT<Twl  by  the  breadth  to  the  forward  propelling 


X 


*'/ 


ftlMO  PPeSSt^ffE 


i-K.   ;!0I.     U\,\\t,r\\\\\  kA  wind  forcc?i  acting  on  aail 


lofM'  l'|{.  iu\\.ri\\\\'\\\\\  tlic.  boat  is  moved  by  the  wind  in  a 
<ln<'(lion  |>ii.rnll('l  t^>  the.  k<;«'l. 

Ifi'li-i  Mii.i  roiKiitinn  of  wind  pressure,  the  leeward  force  is 
rofnhiiillv  <-\«-ilin;'  an  inlliMMice  on  tin;  boat,  tending  to  drive  the 
boiil.  nil  lii'i  roiii.'.r.  but  tin*  proprlliiij^  force,  which  is  sometimes 
M-b'iH-(l  to  JIM  till-  lorcr  prodnc'in;:  angular  velocity,  will  be  in 
i^xri-.'.,!  ol  till'  liM'WJud  lone  provicb'd  the  mast  and  sails  are  placed 
\\\  tlicn  «'ori«>(-t  poi^itions. 

Fowur  lo  Carry  Sail.  It  is  considt'red  that  sufl&cient  informa- 
tion Ini.i  jibi'jMJy  JH-cn  ^'ivrn  in  Section  C,  Part  II.,  to  enable  the 
rrjnl'T  to  inMlrrstiuHJ  tlir  various  (polities  of  a  boat  in  order  that 
MJM*.  will  n*niain  in  a  st.ablr.  condition  when  in  a  seaway.  There 
is  a  fnrt-lMT  jpudity  which  a  boat  must  possess  to  be  an  effective 
lilcMiivin;.'  a|>|>liancc,  should  sIm»  b(^  within  a  reasonable  distance 
from  hind,  and  h-ft  U^  her  own  resources  :  'that  (piality  is  termed 
*'  the  power  to  carry  sail." 

Centre  of  EfTort.  -One  of  the  lirst  consideratiims  is  the  position 
of  the  •*  centre  of  elTort  "  and  the  "  centre  of  lateral  resistance." 


SAILS 


359 


The  centre  of  effort  (CE)  is  really  the  centre  of  gravity  of 
the  sail  area.,  or  the  point  at  which  the  resultant  of  the  wind 
forces  spread  over  the  sail,  is  assumed  to  act ;  or  in  other  words, 
the  centre  of  effort  is  the  position  where  the  accumulated  effort 
of  the  wind  is  assumed  to  be  centred  or  controlled. 

The  sails  generally  used  on  ships'  boats  are  the  standing  or 
dipping  lug  and  the  jib. 

The  "  centre  of  effort "  of  a  sail  plan  is  found  as  follows : — 

Reference  must  be  made  to  Fig.  202. 


/     CE.NT/t£0r£f-FO/fT  Or  JIB 

z  ccN 7P£  oTE^roffr  or  LUG 

3   CENTftE  or£ffOPr  Of  fUlL 
SAIL  ARCfk 


Fig.  202.— Method  of  finding  the  centre  of  effort  of  sail  area. 

Take  the  jib  of  triangular  shape,  bisect  foot  FG,  and  draw  a 
line  to  E. 

Bisect  the  luff  FE  and  draw  a  line  to  G. 

The  intersections  of  these  two  lines  within  the  triangle  EFG 
will  be  the  centre  of  effort  of  the  jib. 

We  next  deal  with  the  lug-sail. 

The  same  principle  of  working  is  used  with  the  dipping  as  in  a 
standing  lug. 

Draw  a  diagonal  line  from  throat  at  B  to  the  clew  at  D,  thus 
dividing  the  sail  into  two  triangular  portions. 

Proceed  as  in  the  case  of  the  jib  to  find  the  centre  of  gravity 


360  SHIPS'  BOATS 

of  each  triangle.  Join  these  two  points,  and  divide  the  line 
inversely  as  the  sail  areas,  to  give  the  centre  of  effort  of  the 
standing  lug-sail. 

In  the  case  where  a  boat  is  fitted  with  a  standing  lug  and  jib, 
as  illustrated  in  Fig.  202,  it  is  necessary  to  find  the  area  of  each 
individual  sail,  and  the  position  of  the  "centre of  effort,"  relative 
to  th^  "  centre  of  lateral  resistancey"  and  the  stem  or  middle  of 
length  of  boat.    The  procedure  is  as  follows  : — 

(a)  Multiply  the  area  of  the  jib  by  the  distance  between  its 
centre  of  effort  and  the  centre  of  lateral  resistance. 

(b)  Repeat  the  operation  for  the  lug  sail. 

If  we  add  together  the  result  of  (a)  and  (6)  we  obtain  the  total 
vertical  moment,  and  dividing  this  quantity  by  the  total  sail 
area,  we  obtain  the  final  position  of  the  centre  of  effort  of  the 
whole  sail  area,  relative  to  the  centre  of  lateral  resistance. 

To  obtain  the  fore-and-aft  position  of  the  centre  of  effort,  we 
take  moments  about  a  vertical  line  at  the  mid-length  of  the  boat, 
and  proceed  in  the  same  way  as  we  did  with  the  vertical  moments, 
dividing  the  total  moment  by  the  total  sail  area.  Where  the 
horizontal  line  drawn  through  the  centre  of  effort  in  its  relation 
to  the  centre  of  lateral  resistance,  intersects  the  vertical  line 
drawn  through  its  position  relative  to  mid-length,  centre  of  mast, 
or  front  of  stem,  whichever  is  used,  that  point  of  intersection 
is  the  centre  of  effort  of  the  whole  sail  area. 

An  example  wiU  simplify  the  explanation.  Take  the  sail  areas 
for  a  28-ft.  Class  Ia  hfeboat,  viz.  : 

37  sq.  ft.  for  the  jib,  and 

1G3  sq.  ft.  for  the  standing  lug. 


Q„„         Area  In       Distance  between  Vertical        '  ^ri*?nrvL^«ir^'*    Horizontal 

"*"•         sq.  ft.  CE  and  CLR.  moments,      i       mid-length  niomentt*. 


Jib  37  8-7  ft.  321-9  93    ft.  '      .3441 

Lug  1()3  0-5  ft.  1548-5  -65  ft.  89G5 


Total  area  =  200  sq.  ft. 
Total  vertical  moment  =  1870*4 
Total  horizontal  moment  =  433*75 

Vertical  position  of  CE  above  CLR  =  *^"?^  =  9  35  ft. 
^  200 

Ditt^,  above  bottom  of  keel  =  10*35  ft. 

433*75 
Horizontal  position  of  CE  forward  of  mid-length  of  boat  ='   ^ru.    =2*17  ft. 


SAILS  , 


361 


Centre  of  Lateral  Resistanee.  (CLB)  is  the  centre  of  gravity 
of  the  immersed  longitudinal  plane  of  the  boat. 

Angle  of  Heel  Produeed  by  Wind  Pressure. — ^Referring  to 
Fig.  203— 

h  is  the  vertical  height  between  CE  and  CLR.    There  are  four 


P. 


1 


CE 


■f 


f/ 


P5 
Fio.  203. 

forces  in  operation  and  exerting  an  influence  on  the  boat,  viz. : 

Pi  =1  The  horizontal  pressure  of  wind  on  sails. 

P2  =»  The        „  „  water  on  the  hull. 

P3  =1  The  vertical  downward  force  of  gravitation. 

P4  =  The  vertical  upward  force  of  buoyancy. 

Pi  and  P2  tend  to  upset  the  boat,  acting  at  a  leverage  A. 

P3  and  P4  tend  to  right  her,  and  6Z  is  the  righting  lever. 

When  the  vessel  is  at  a  steady  angle  of  heel  0,  we  have — 

WxGZ=.PiXA 

W  =  the  weight  of  the  boat  in  lbs. 

A  wind  of  about  14  knots  (fresh  breeze)  is  taken  as  giving  a 
pressure  of  1  lb.  per  sq.  ft. 

For  small  angles  of  inclination — 

GZ  =  GM  sin  0 

Pj  =/A,  where  /=  lbs.  pressure  per  sq.  ft.,  and  A  =  area  of 
sails  in  square  feet. 

Then  W  X  GM  sin  0=/A  X  h 

'    n       /A  X  A 
sin  0  =3  -      -  _ 

WxGM 


362  SfflPS'  BOATS 

If  the  wind  pressure  is  1  lb.  per  sq.  ft.,  then  the  formula  is 

Ml 


sin  6  = 


WxGM 
WxGM 


If  we  invert  the  quantity  to  we  arrive  at  the  value 

of  the  "  jpoiDer  to  carry  saiV 

Take  the  example  previously  worked  out  for  the  position  of  the 
centre  of  effort. 

A  (area  of  sails)  =  200  sq.  ft. 
h  (distance  between  CE  and  CLR)  ==  935  ft. 

Total  weight  of  loaded  boat  =  12992  lbs.  (5?8  tons) 

Assume  6M  =  1-5  ft. 

.    .      200  X  9-35 
Then  sm  fl  =  j2992^^r5  =  °  ^^ 
Angle  of  heel  =  5  J  degrees. 

If  we  are  provided  with  the  stability  curve  of  a  boat,  area  of 
sails,  wind  pressure,  and  height  between  centres  of  effort  and 
lateral  resistance,  we  can  readily  obtain  the  angle  of  heel,  because 

WxGZ  =  PiXA 
and  GZ  =  -^if 

w 

P  h 
Take  the  value  of    ^  ,  and  set  this  off  from  the  base  line 

of  the  stability  curve  and  through  it  draw  a  parallel  line  cutting 
the  curve  at  a  point,  which  will  quickly  give  us  the  angle  of  steady 
heel. 

Dynamical  Stability  expresses  the  amount  of  work  done  when 
incUning  a  boat  from  the  upright  to  a  given  angle.  It  is  the  sum 
of  the  products  of  the  force  multipUed  by  the  distance  moved 
through,  at  every  an<^'le  of  inchnation  from  the  upright  to  the 
resulting  angle  of  heel. 

The  area  of  the  curve  of  statical  stabiUty  up  to  any  angle, 
measures  the  dynamical  stability  at  that  angle.  The  ordinates 
of  the  curve  must  represent  the  actual  righting  moments,  i.e.  the 
righting  levers  at  any  angle  are  multiphed  by  the  weight  of  the 
boat  or  measure  of  displacement. 

In  this  connection  we  see  that  the  greater  the  area  enclosed  by 
the  curve  of  statical  stabihty,  the  greater  will  be  the  amount  of 
work  that  is  necessary  to  be  done  to  incline  the  boat  to  that  angle 
which   brings  the  gunwale  to  the  surface  of  the  water,  which 


SAILS 


363 


angle,  for  a  lifeboat,  will  in  reality  be  the  vanishing  au|;le  of 
stability. 

Relation  between  Stability  and  Wind  Pressure  Curves. — The 
efiective  are^  of  a  sail  becomes  less  as  the  angle  of  inclination 
Lucreaaes.  The  moment  of  preJ^sure  is  j^re-ateat  when  the  vessel  is 
upright,  and  is  zero  when  the  sails  are  horizontal  or  parallel  to  the 
water-line. 

Fig.  204  shows  the  statical  stability  curve  of  a  ship's  boat,  and 
indicated  thereon  is  also  a  ciirve  of  momenta  of  wind  pressure 
at  each  angle  of  heel. 

If  P=ithe  wind  preaaiire  in  lbs.  per  sq.  ft.,  moving  in 
a  horizontal  direction  upon  the  Jull  sail  area,  when  the  vessel 
inclines  to  an  angle  6,  correctly  speaking  the  pressure  on  the 
sails  =>  P  X  A  X  cos  6,  and  the  effective  arm  =  h  cos  $.  {See 
Fig.  205.)  The  moments  of  wind  pressure  are  set  up  at  the 
various  degrees  of  heel  and  we  obtain  a  curve  tibf  (aea  Fig.  204). 
The  "  work  done  "  by  the  upsetting  force  of  the  wind  up  to  an 
angle,  say  5J°,  is  the  area  dabe,  and  the  opposing  forces  to  in- 
clination represented  by  the  rigliting  moments,  up  to  the  same 
angle  of  heel,  is  the  area  dlx:  The  boat  will  be  heeled  over  to 
the  angle  at  which  the  energy  given  it  by  the  excessive  wind 
pressure  on  the  sails,  is  overcome  by  its  reserve  stability,  i.e.  to 
an  inclination  1 1 V.  where  the  shaded  area  bef  equals  dab  (see 
Fig.  204).  From  the  figure  it  will  be  seen  that  a  sudden  squall 
will  probably  heel  the  boat  to  twice  the  inclination  that  woidd 
be  caused  by  a  steady  wind. . 

When  a  boat  is  rolling  with  sails  set  and  on  a  leeward  heel, 
i.e.  inclined  against  the  wuid  pleasure,  and  she  is  suddenly 
struck  by  a  squall,  a  much  greater  angle  of  inclination  will  be 
reached  than  the  one  previously  referred  to  when  the  boat  was 
struck  by  a  squall  in  the  upright  position. 

Referring  to  Fig.  206.     The  same  force  of  wind  is  blowing 

which  is  eslimated  to  incline  the  vessel  to  an  angle  of  5i°  steady 

heel.     Assuming  the  boat  to  be  at  a  leeward  roll  of  11  J",  and 

suddenly  struck    by  a   squall,   we  find  under  this   condition 

that  the  righting  moment   and  the  wind  pressure  are    acting 

together  in  the  same  direction.     The  boat,  after  reaching  the 

upright  condition,  will  continue  to  heel  until  the  shaded  areas 

^L        (a.s    previously    explained)    are    equal.      After    reaching    the 

^H        maximum  angle  of  inclination  at  17°  she  will  gradually  return 

^H       to  the  steady  angle  of  heel.  viz.  5p. 

^1  The  theoretical  consideiation,  connected  with  the  question  of 

^1       sails  has  been  reduced  to  a  minimum,   but  sufficient  has  been 


i 


364 


SHIPS'  BOATS 


stated  to  impress  upon  the  reader  the  necessity  for  taking  into 


W^        7s*  itcf 

-  ANGLES  OFH££L  - 
Fio.  204. 


wr.£" 


erre^crtvc  sa/l 
AR£A  mA.CosB 


it.    ANGLE  OF 
67eAOYH££L  S>C 


CI.R, 


Fro.  205. 


fo-  15*    I  20* 

-  ANCLCS  OFHECL  — 

Fia.  206. 


consideration  the  far-reaching  effects  of  wind  pressure  on  sail 
area,  and  their  relation  to  the  question  of  suitabiUty  of  form,  to 


SAILS 


365 


provide  the  best  qualities  for  enabling  a  boat  to  remain  stable 
under  the  various  conditions  she  may  meet. 

Suitable  Areas  for  Sails. — Table  XXIV.  gives  in  detail  the 
areas  in  square  feet  for  the  various  sails  which  are  considered 
suitable  for  the  particular  size  of  boat.  Figs.  207-214  illustrate 
each  individual  sail  plan  with  figured  dimensions. 

TABLE   XXIV. 
Sail  Areas  fob  Open  Boats  op  Classes  I.  and  III. 


Figure. 

Tiongth  of  boat 
in  feet 

Type  of  sail. 

Area  in  sq.  ft. 

207 

15  &  16 

Dipping  lug 

79 

207a 

15  &  16 

Standing  lug 

68* 

208 

17  &  18 

Dipping  lug 

93 

208a 

17  &  18 

Standing  lug 

72* 

209 

19&20 

Dipping  lug 

120 

209a 

19  &  20 

Standing  lug 

91* 

210 

21  &22 

Dipping  lug 

138 

210a 

21  &22 

Standing  lug 

112* 

211 

23&24 

( Standing  lug 
\Jib 

124 

28 

211a 

23&24 

Standing  lug 

138* 

212 

25  &  26 

(Standing  lug 
IJib 

145* 
30* 

213 

1         27  &  28 

(Standing  lug 
\Jib 

165* 
34* 

214 

29  &  30 

/Standing  lug 
\Jib 

198* 
38* 

*  Sizes  approved  by  the  Board  of  Trade. 

In  Figs.  207-211  there  is  shown  in  addition  to  the  dipping 
lug-sail,  a  standing  lug  indicated  in  ticked  lines.  It  has  been 
advocated  by  many  ships'  officers  and  practical  boatbuilders 
that  the  position  of  the  rriast,  when  the  boat  carries  a  single  lug, 
is  at  the  first  thwart,  to  enable  the  tack  of  the  sail  to  be  brought 
down  to  the  head  of  the  stem, and  thus  allow  the  boat  to  sail  close 
to  the  wind.  Recently  there  has  been  an  alteration  in  the 
governing  regulations,  making  it  permissible  to  fit  the  mast  at 
the  second  thwart  with  a  standing  lug  sail.  This  recommendation 
appears  to  be  opposed  to  all  the  rules  of  sailing,  but  the  details 
are  inserted  for  general  information. 

The  areas  and  details  shown  in  full  lines  in  the  various  plans 
referred  to  are  suggested  as  the  most  suitable  for  the  purpose  of 
providing  a  rapid  means  of  reaching  safety  when  the  conditions 
of  wind  and  weather  will  allow.    The  areas  are  considered  to  be 


366 


SHIPS'  BOATS 


sufficient  for  the  purpose,  and  at  the  same  time  not  too  large 
to  become  detrimental  to  the  boat's  stability.    They  have  been 


Fra.  207. — Sail  plan  for  16  and  16-ft.  open  boats  of  Glasses  I.  and  III. 

drawn  up  by  practical  sailmakers  and  worked-to  by  a  large  number 
of  boatbuilders  during  the  past  three  years.  It  naturally  follows 
that  perniission^for  fitting  a  standing  lug  at  the  second  thwart 


Fig.  208. — Sail  plan  for  17  and  18-ft.  oi>en  boats  of  Classes  I.  and  III. 

will  be  followed  by  the  majority  of  the  firms,  in  view  of  the 
reduced  cost,  and  the  enforcement  of  standard  regulations. 


SAILS 


367 


There  is  quite  a  divided  opinion  as  to  whether  it  is  essential 
or  advisable  to  fit  all  the  lifeboats  of  a  foreign-going  passenger 


A 


/ 


4 


1r. 


^i. 


Fio.  209. — Sail  plan  for  19  and  20-ft.  open  boats  of  Classes  I.  and  Til. 

steamer,  employed  in  the  North  Atlantic  trade,  with  masts  and 
sails.    Provided  the  vessels  are  fitted  with  wireless  telegraphy 


y.  jo^o — 


F[0.  210.--Sail  plan  for  21  and  22ft.  open  boats  of  Classes  T.  and  III. 


apparatus,  the  Life-saving  AppUances  Rules  make  provision  that 
only  four  of  the  lifeboats  need  be  equipped  with  masts  and  sails. 


368 


SHIPS'  BOATS 


One  of  the  reasons  for  the  inclusion  of  this  clause  is  that  when 


Fio.|  211.— Sail  plan  for  23rand^24-ft.'open  boate  of  Class  I. 


Fio.  212.— Sail  plan  for  25  and  2(>-ft.  oik-u  boata  of  Class  I. 

disaster  overtakes  a  vessel,  it  is  naturally  assumed  that  wireless 
messages   have   been   despatched,    giving   the   exact   position, 


SAILS 


369 


Fio.  213. — Sail  plan  for  27  and  28-ft.  open  boats  of  Class  I. 


Fio.  214.— Sail  plan  for  29  and  30-ft.  open  boats  o|  Class  I. 

and  it  is  therefore  to  the  advantage  of  the  occupants  to  stay 
within  the  immediate  neighbourhood  of  the  disaster  until  the 

2  B 


370  SHIPS'  BOATS 

arrival  of  help.  The  boats  should  keep  within  reasonable  distance 
of  each  other,  and  ride  with  the  aid  of  the  sea  anchor.  If  all  the 
boats  are  equipped  with  sails,  and  efforts  were  mcMie  to  set  sail 
in  favourable  weather,  they  might  get  widely  separated,  and  the 
operation  of  rescue  would  become  increasingly  difficult.  It 
largely  depends  on  circumstances,  and  the  position  or  area  in 
which  the  disaster  occurs.  It  usually  happens  that  the  pre- 
vailing conditions,  when  serious  difficulty  overtakes  a  vessel, 
are  quite  the  opposite  to  what  were  anticipated ;  however,  if  the 
occupants  of  a  lifeboat  are  within  reasonable  distance  of  land,  a 
spread  of  sail  is  considered  an  advantage  to  enable  them  to  arrive 
at  a  port  as  quickly  as  possible,  particularly  when  there  are 
wounded  persons  on  board. 

The  boats  for  Home  Trade  vessels  need  not  be  Supplied  with 
masts  and  sails,  as  the  distance  separating  the  port  of  departure 
and  arrival  is  not  considered  sufficient  to  demand  their  inclusion 
in  the  equipment.  In  isolated  cases  they  have  been  provided 
at  the  direct  wish  of  the  shipowner.  The  seamen  of  vessels 
thus  equipped,  during  the  submarine  menace  around  the  coasts 
of  Great  Britain,  derived  a  great  advantage  from  the  inclusion 
of  some  means  of  propulsion  beyond  the  use  of  oars,  which 
lessened  their  sufferings  when  it  became  necessary  to  abandon 
the  ship. 

There  is  one  point  to  which  attention  is  particularly  drawn. 
In  the  case  of  certain  foreign-going  cargo  vessels,  boats  of  Class  III. 
are  included  in  the  statutory  equipment.  They  must,  therefore, 
be  fitted  with  masts  and  sails,  and  equipped  in  every  particular 
like  the  remaining  lifeboats,  except  that  buoyancy-tanks  are  not 
required  to  be  fitted. 

Details  of  Sails. — The  various  parts  of  a  sail  are  illustrated 
in  Fig.  215. 

Tlie  material  of  all  t>ails  should  be  made  from  good  quaUty 
linen  duck  or  an  approved  canvas. 

The  threads  of  the  sail  cloth  worked  across  are  called  the 
'*  ivvjtr  and  those  which  run  in  the  opposite  direction  over  and 
under  the  weft  are  calleil  the  *'  icarp.^'  The  "  selvage  "  is  the 
edge  of  the  doth. 

The  cloth  is  cut  in  relation  to  the  run  of  the  "  weft "  and 
"  war}),''  taking  into  account  the  amount  of  stretching  which 
takes  place,  so  as  to  give  the  best  results  for  a  good  setting  sail. 

It  is  iionerallv  considered  that  a  ''flat  "  sail  is  the  best  form  of 
sail  to  enable  a  boat  to  sail  close  to  the  wind.  A  bagg}'  sail  tends 
to  burv  the  bow  of  a  boat  and  hold  her  back.     A  flat  sail  has  more 


SAILS 


371 


lifting  power,  and  while  securing  the  maximum  amount  of  wind 
pressure,  allows  the  air  easier  freedom  for  exit  from  the  after 
leach. 

A  well-made  sail  can  be  spoiled  by  the  operation  of  bending. 
A  lug-sail  must  be  fairly  slack  when  first  bent  on  the  yard.  The 
peak  and  throat  are  secured  to  the  yard  by  seizing,  and  the  lacing 
should  be  commenced  from  the  centre  of  the  yard,  working 
towards  the  peak  and  throat.  The  usual  practice  is  to  reeve 
the  lacing  through  the  eyelet-hole  in  the  sail,  over  the  yard,  and 
bring  it  back  through  the  same  eyelet-hole,  make  a  half-hitch, 


SMfKMO 
HOOP 


MEAD 


SO/r 


Fig.  216. — ^Details  of  sails. 


and  work  the  lacing  along  the  head  of  the  sail  to  the  next  eyelet- 
hole,  until  the  operation  is  completed  at  the  peak  and  throat  by 
securing  the  lacing  by  two  half-hitches. 

The  sails  should  be  used  once  or  twice  to  provide  for  stretching, 
and  then  rebent  on  the  yards. 

The  holes  in  the  yards  which  take  the  seizings  for  peak  and 
throat,  are  usually  kept  about  6  in.  beyond  the  length  of  the  head 
of  sail,  to  allow  for  stretching. 

The  position  of  the  strop  on  the  yard,  which  is  attached  to  the 
halyards,  is  of  some  importance,  to  enable  the  sail  to  set  properly. 
The  position  for  a  lug-sail  can  be  found  by  actual  trial  when  first 


372 


SHIPS'  BOATS 


spreading  the  sails,  but  roughly  indicated,  the  position  for  a 
dipping  lug  is  at  about  one-third  the  length  of  the  yard  from  its 
fore  end,  and  a  quarter  the  length  for  a  standing  lug. 

The  bolt  rope  should  be  of  substantial  dimensions  and  quality 
and  worked  the  full  length  of  the  lu£E  and  head  of  sail,  also  at  the 
edges  of  the  clew  and  peak. 

Each  sail  must  be  fitted  with  reef  points,  and  a  substanticJ 
thimble  and  cringle  secured  at  the  clew  and  tack. 

The  usual  practice  has  been  to  fit  a  standing  lug  and  a  jib  for 
boats  down  to  and  including  24  ft.  in  length,  the  mast  being 
stepped  at  the  second  thwart. 

In  boats  of  23  ft.  in  length  and  under,  a  dipping  lug  only  is 


ELEVATION  SECTION 

Fig.  216. — Method  of  fitting  tack  hooks. 


fitted,  with  the  mast  stepped  at  the  first  thwart,  so  as  to  aUow 
the  tack  of  the  sail  being  brought  down  to  the  head  of  the  stem. 

To  facilitate  the  operation  of  dipping  the  sail,  a  "  tack  hook  " 
is  fitted  on  the  stem  or  apron  head,  usually  behind  the  breasthook, 
as  shown  in  Fig.  216.  The  sail  is  not  lowered  when  dipping,  but 
the  halyards  are  slackened  sufficiently  to  allow  the  tack  to  be  un- 
hooked at  the  stem.  The  fore  yardarm  is  then  dipped  from  one 
side  of  the  mast  to  the  other,  the  tack  being  re-hooked  at  its 
original  position. 

It  used  to  be  quite  a  common  practice  to  fit  the  mast  at  the 
second  thwart,  with  only  a  standing  lug-sail ;  this  is  a  practice 
which  should  be  condemned. 

]A  boat  fitted  with  a  dipping  lug  having  the  tack  brought 
down  to  the  stem  or  with  a  standing  lug  and  a  jib,  is  able  to  sail 
closer  to  the  wind  with  less  drift  to  leeward,  and  possesses  greater 


W      lug  gtt* 


SAILS 


373 


liiting  power  than  a  boat  which  ia  only  supplied  with  a  standing 
lug  fitted  at  the  second  thwart.  The  first  method  also  helps 
to  keep  the  boat  from  pitching  in  a  head  sea. 

Sail  Bag. — A  painted  canvas  sail  bag  is  not  a  requirement 
of  the  L.S.A.  Rules,  but  it  is  a  very  necessary  inclusion  in  the 
equipment  of  a  boat,  The  writer  has  repeatedly  seen  aaila  made 
useless  by  the  action  of  the  weather,  a  difficulty  which  can  easily 
be  remedied  by  the  provision  of  a  suitable  cover. 

Shrouds. — Every  boat  supphed  with  masta  or  sails  should  be 
fitted  with  wire  or  suitable  hemp  shrouds  on  each  side  of  the 
mast,  set  up  to  proper  shrciud  plat*a  of  good  quality  and  secured 
with  through  clenched  fastenings.  Fig.  197  b  shows  the  usual 
shape  of  plate  supplied  for  the  purpose. 

A  common  practice  is  simply  to  fit  a  plate  of  sufficient  depth 
to  suit  the  gunwale,  and  secured  to  the  latter  by  a  couple  of 
screws.  The  most  satisfactory  type  of  fitting  is  a  substantial 
plate  secured  on  the  outside  of  the  sheer  atrake,  joggled  over 
the  rubber  and  fastened  by  through  clenched  fastenings  at  the 
gunwale  and  rubber. 

It  is  considered  shoddy  work  to  simply  splice  the  shrouds  over 
the  peak  of  the  mast;  proper  iron  hoops  should  be  fitted  as  shown 
in  Fig.  219. 

Mast  Hasp,— This  should  he  of  substantial  scantling  and  so 
arranged  that  the  securing  pin  is  easily  inserted  and  withdrawn, 
The  necessity  for  driviug  tlie  securing  pin  must  be  avoided  for 
obvious  reasons.  The  arms  of  the  hasp  are  secured  to  the  thwarts 
by  through  copper  rivets  well  clenchwi,  as  indicated  in  Fig.  217, 
or  by  ordinary  nut  and  screw  bolts,  the  nuts  being  hove  up  on 
the  arm  under  the  thwart.  Securing  the  arms  by  ordinary  screws 
is  a  useless  and  dancerous  practice. 

Two  niethorls  of  forming  the  mast  hasp  are  shown  in  Figs.  217 
and  318.  The  latter  is  considered  the  better  job  of  the  two. 
More  time  is  necessarily  taken  in  fitting  the  mast,  conse- 
quently, greater  expense  is  incurred,  but  the  additional  outlay  ia 
more  than  compensated  by  the  provision  of  a  better  security  at 
the  thwart,  which  relieves  the  stress  on  the  mast  step. 

Details  of  mast  steps  are  dealt  with  in  Section  A  of  Part  IV. 

Halyard  Sheaves.— Care  must  of  necessity  be  taken  in  fitting 
the  mast  sheaves  to  take  the  jib  and  lug-sail  halyards.  The  jib 
is  fitted  above  the  lug  sheave,  and  both  look  in  a  fore-and-aft 
direction. 

The  sheaves  are  securely  attached  to  the  mast  with  a  clenched 
bolt  or  pin,  and  not  simply  driven  in  from  one  side  only,  to  avoid 


374 


SfflPS'  BOATS 


clenching.  It  is  these  small  detail  fittings,  slovenly  attached  to 
the  mast,  and  considered  of  little  importance,  which  are  responsible 
for  many  difficulties. 

To  prevent  the  mast  swelling  through  the  action  of  the  weather 
and  jamming  the  sheave,  sheet  copper  should  be  neatly  tacked 
in  and  around  the  slot  in  the  mast  as  shown  in  Fig.  220. 

Mast  Traveller. — A  convenient  form  of  mast  traveller  is 
shown  in  Fig.  221  ;  the  fitting  should  be  of  substantial  section 
and  of  such  a  pattern  that  when  hoisted  by  the  halyards  it  does 


u 


/4 


3 — ^ 


V     4'     \!      ^ 


-  eL£V AT/ON 


;4  CoppcR 


-  PlAN- 


^\    ©       Q       Q^ 


Fig.  217.  Fio.  218. 

Details  of  mast  clam^is  and  hasps. 

not  jam  with  the  mast.  The  experience  of  the  writer  may  have 
been  an  unfortunate  one  in  this  respect,  but  it  is  safe  to  say  that  a 
large  number  of  these  detailed,  but  nevertheless  important, 
fittin<^^s,  connected  with  the  rigging  of  ships*  boats,  now  placed 
on  the  market,  are  considered  very  poor  and  unsuitable  for  the 
purpose  required. 

it  will  be  noticed  that  the  type  of  traveller  shown  in  Fig.  221, 
has  the  (ye  of  the  hook  attached  to  the  halyards,  and  so  shaped 
as  to  allow  the  traveller  to  slip  up  the  mast  easily,  and  without 
a.ssi.stance  by  any  other  means  than  the  halyards. 


SAILS  -      375 

Sheet  Cleats.— The  sheets  atfiiched  to  the  clew  of    the  jib 


AthwarWhip  view.  Fore-and-aft  viow. 

Fia  221.  — DcUils  of  most  trsTollcr. 

should  l>n  dimble,  and  led  through  eye-plat«B  out  of  the  way  of 
tlie  passenj;er3,  to  strong  cleats  attached  to  the  gunwale  in  the 


376 


SHIPS'  BOATS 


stem-sheets.  The  cleats  for  securing  the  sheet  attached  to  the 
clew  of  the  lug-sail,  are  usually  fitted  just  abaft  the  knee  on  the 
aftermost  thwart,  so  that  all  the  sheet  ropes  are  under  the 
control  of  the  officer  in  the  stem-sheets. 

A  typical  sheet  cleat  is  shown  in  Fig.  197  a.  It  is  the  usual 
type,  but  it  should  be  well  secured  to  the  gunwale  and  large 
enough  for  the  purpose  for  which  it  is  intended. 

Length  of  Masts. — The  length  of  masts  must  not  exceed 
two-thirds  the  length  of  the  boat.  Table  XXV.  gives  the  lengths 
for  the  various  open  boats  of  Classes  I.  and 'III.  The  length  is 
taken  from  the  heel  of  the  mast  to  the  centre  of  the  upper  halyard 
sheave,  so  that  when  the  normal  peak  is  given  to  the  lug-sail  the 
steersman  will  have  no  difficulty  in  possessing  a  full  unobstructed 
view  under  the  foot  of  the  sail. 


TABLE   XXV. 
Length  and  Sizes  of  Masts  for  Open  Boats  of  Classes  I.  and  III. 


LengU)  of  Boat  iu  feet. 

Length  of  Mugt 
from  heel  to  centre  of 
upper  halyard  sheave. 

10'  0" 

Diameter  of  Mast 
at  thwart 
in  inches. 

15  &  16 

2j" 
3^' 

17  &  18 

iro" 

19  &20 

12'  6" 

.Si" 

21  &22 

14'  0" 

3i" 

23  &  24 

15'  0" 

3}" 

25  &  2H 

hV  0" 

4" 

27  &28 

18'  0" 

4J" 

29  &  30 

19'  0" 

4i" 

Note. — Tlic  above  lengths  of  masts  are  in  accordance  with  the  Board  of 
Trade  standard  sail  areas.  If  dipping  lug-sails  aie  fitted,  the  full  length  of 
mast  is  required,  equal  to  two-thirds  the  length  of  the  boat;  e.g.  a  16-ft.  dinghy 
requires  a  mast  10'  8"  in  length. 

The  diameter  of  yards  to  be  from  2"-2J"  for  a  left,  boat  to  2J"-3J"  for 
a  30-ft.  boat,  which  is  governed  by  the  length  of  head. 

The  masts  are  usually  made  from  well-seasoned  Norway 
spruce.  They  should  be  coated  wath  varnish,  or  white-lead  paint, 
as  a  protection  against  the  weather.  Ordinary  white  pine  is  of 
little  value,  as  it  quickly  spht^,  and  is  unsuitable  for  spars. 

An  old  nile  for  obtaining  the  diameter  of  ships'  masts  was 
1  in.,  and  for  cutters  £  in.  for  every  3  ft.  of  length.  This  is 
hardly  apphcable  for  masts  of  ships*  boats,  as  it  would  make  them 
too  heavy  for  the  operation  of  stepping,  which  might  probably 
have  to  be  done  when  the  boat  is  full  of  persons.  Nevertheless, 
the  mast  must  be  strong  enough  to  carry  the  approved  area  of  sail. 


METHODS  OF  GALVANISING 


37T 


I 


The  practice  of  fitting  a  standard  aize  of  mast  hasp  for  all 
sizes  of  boate  should  be  condemned.  It  stands  to  reason  that 
the  smaller  boat^  are  overweighted  with  so  lieavy  a  mast,  while 
the  larger  ones  are  supplied  with  masts  insufficient  in  strength. 
The  reference  may  appeal  to  some  builders  who  limit  their  stock 
of  fittinf;s  to  small  proportions. 

General  Remarks.—Carelesaneas  and  insufficient  attention 
to  small  details  often  spoil  the  good  work  put  into  the  actual 
construction  of  the  boat.  It  is  the  extra  ten  minutes  spent  on 
the  "  finishing  off,"  althougli  not  materially  affecting  the  boat  as 
a  hfe-saving  appliance,  that  undoubt«dly  adds  to  the  appearance 
and  increases  her  lasting  qualities. 

If  a  mechanic  is  given  good  material  to  work  with  he  will 
naturally  take  a  more  personal  interest  in  the  construction,  and 
endeavour  to  produce  a  boat  that  will  be  consistent  with  the 
quality  of  the  material.  In  a  similar  way,  if  boats  of  l^e 
highest  class  are  placed  on  board  passenger  and  cargo  veesek, 
having  a  good  finished  appearance,  the  ship's  officer  responsible 
for  the  upkeep  of  the  lifeboats  will  take  a  keener  interest  in  his 
work  than  if  the  boats  are  poorly  constructed  and  lack  a  finished 
appearance.  Ships'  officers  do  not  profess  to  be  boatbuilders, 
but  experience  has  taught  them  what  equijmient  is  necessary, 
and  the  quafity  of  details  which  should  be  provided  in  order 
that  they  may  be  effective  for  the  purpose  they  have  to  serve. 

There  is  no  doubt,  for  many  years,  that  insufficient  attention 
has  been  paid  by  shipbuilders  and  boatbuilders  to  the  question 
of  providing  suitable  sails  and  their  component  details.  In 
fairness  to  the  builders,  it  should  be  stated  that  the  ruies  and 
regulations  were  not  clear  on  the  -subject.  However,  the  reference 
to  the  importance  of  these  matters  is  not  considered  out  of  place. 


SECTION  C— METHODS  OF  GALVANISING 

It  is  very  essential  in  the  construction  of  all  metallic  bnata  and 
fife-rafts,  that  the  steel  or  iron  should  be  carefully  and  efficiently 
galvanised.  One  of  the  difficulties  which  meets  the  builder  is 
that  of  securing  a  satisfactorj-  system  of  galvanising  in  way  of 
those  portions  of  the  hull  which  have  been  welded  together. 

The  standard  practice  in  the  boat-yards  of  Great  Britain  is 
to  galvanise  the  steel  plating  of  metallic  boats  inside  and  outside, 
with  the  addition  of  a  coating  of  bitumastic  enamel  on  the  inaide, 
if  desired. 

The  United  States  Steamboat  Inspection  Service  requires  all 


378  SHIPS'  BOATS 

the  shell  plates,  air-tanks,  nails,  gunwale  braces,  rudder  braces, 
and  fastenings  of  metallic  boats  to  be  galvanised. 

The  riveting  must,  therefore,  be  performed  in  such  a  manner 
as  to  prevent  the  galvanised  surface  of  the  plates  from  becoming 
injured,  and  exposed  to  the  corrosive  effect  of  sea  air,  and  water. 

Corrosion  is  the  deadly  enemy  of  the  metaUic  boat.  It 
therefore  becomes  necessary  to  frequently  inspect  the  interior  to 
ascertain  the  actual  condition  of  the  hull^ 

An  internal  coating  of  some  protective  composition  goes  a 
long  way  towards  the  prevention  of  the  difficulty,  as  frequent 
observation  during  the  survey  of  boats  has  often  proved. 

All  iron  or  steel  work  used  in  the  construction  of  wooden  life- 
boats must  be  heavily  galvanised.  The  omission  of  the  hooks  from 
this  requirement  depends  largely  on  the  process  by  which  the  iron 
is  treated.  If  the  material  is  galvanised  by  the  hot  dipping  system, 
the  structure  of  the  metal  is  exposed  to  imeven  stresses  by  being 
suddenly  plunged  into  a  very  high  temperature  without  the 
opportunity  to  gradually  cool.  Consequently,  the  material  has 
a  tendency  to  become  brittle.  A  system  known  as  that  of 
sherardising  is  well  adapted  to  the  requirements  of  the  boat- 
builder  in  this  respect,  and  no  weakening  effect  takes  place  in  the 
material  during  the  process  of  galvanising. 

Whenever  iron  or  steel  lifting  hooks  have  been  galvanised 
by  the  hot  dipping  process,  they  should  be  tested  after  galvanising, 
and  not  before. 

Of  two  evils  choose  the  less.  The  general  practice  has  been 
to  galvanise  the  keel  plates,  and  thickly  coat  the  Ufting  hooks 
with  a  protective  paint.  Taking  into  consideration  the  dele- 
terious efTect  of  the  action  of  water,  etc.,  on  the  heel  otthe  shank 
of  the  lifting  hook,  which  is  usually  hidden  from  sight,  it  is 
advisable  to  galvanise  the  whole  of  the  iron  or  steel  work. 

Hot  Dipping  Process. — The  iron  is  first  placed  in  a  vat  of 
dilute  acid,  to  remove  all  rust  and  clean  the  surface  for  the  proper 
adhesion  of  the  zinc.  It  is  then  heated  and  inserted  in  molten 
zinc,  which  is  covered  with  a  layer  of  sal-ammoniac  to  prevent 
evaporation. 

The  iron  thus  becomes  coated  with  a  thin  covering  of  zinc, 
which  will  stand  many  years  if  exposed  to  ordinary  wear,  but 
the  action  of  sea  air  has  a  penetrating  effect  upon  the  zinc,  and 
it  becomes  essential  to  watch  for  any  signs  of  con'osion,  particu- 
larly in  way  of  the  liftin^^-hook  keel  plates. 

It  is  not  the  actual  coating  of  the  material  with  the  zinc 
dej)()sit  which  makes  the  iron  brittle,  but  the  influence  of  the 


METHODS  OF  GALVANISING  379 

previous  operation  of  immersing  the  iron  in  the  vitriol  bath.  The 
latter  may  be  too  heavily  charged  with  acid  in  order  to  quickly 
clean  the  material,  and  the  combined  action  of  the  acid  and  the 
hot  zinc  gives  an  appearance  to  the  iron  as  if  the  grain  had  opened 
out  into  long  fissures,  making  the  material  useless  for  the  purpose 
required. 

Another  drawback  to  this  process  is,  when  bolts  are  served  to 
the  boatbuilder  in  their  black  condition,  it  becomes  necessary 
after  they  are  galvanised  to  run  down  the  threads,  consequently 
the  builder  takes  the  line  of  least  resistance,  and  coats  them  with 
galvanising  paint,  which  is  of  little  value.  All  securing  bolts 
should,  therefore,  be  galvanised  at  the  maker's  works  before 
delivery. 

Sherardising. — This  process  differs  from  the  electric  and  hot 
dipping  systems  of  galvanising,  and  has  often  been  referred  to  as 
a  process  of  dry  galvanising ;  but  it  practically  fulfils  the  same 
object  of  covering  iron  or  steel  with  a  coating  of  zinc  in  order  to 
render  them  rustproof. 

Briefly  explained,  the  process  consists  of  placing  the  articles 
in  closed  drums  or  other  suitable  receptacles,  in  contact  with  the 
ordinary  zinc  dust  of  commerce.  The  drum  is  then  placed  in  an 
oven  and  gradually  heated  to  the  required  temperature,  and 
allowed  to  remain  for  a  given  period.  It  is  then  permitted  to 
cool  down  very  gradually,  and  the  articles  when  taken  out  of 
the  drum  are  found  to  be  evenly  coated  with  pure  zinc. 

The  articles  are  passed  through  an  acid  bath  before  being 
placed  in  the  galvanising  drums,  to  clean  the  surface  for  the 
proper  adhesion  of  the  zinc.  Care  has  to  be  exercised  in 
diluting  this  pickUng  bath,  to  avoid  the  difficulties  previously 
referred  to. 

The  temperature  used  when  coating  the  article  with  zinc 
ranges  from  400°  to  600°  Fahr.,  but  in  no  case  does  it  reach  the 
melting  point  of  zinc,  viz.  788°  Fahr.  The  action  of  the  zinc  is 
to  root  itself  into  the  material,  forming  a  surface  alloy ; 
when  a  thick  coating  has  been  deposited,  the  top  portion  may  be 
brittle,  and  although  it  may  scale  or  crack  off,  it  leaves  under- 
neath a  malleable  metallic  coating,  and  below  that  again  the 
surface  allov. 

The  coating  is  of  a  very  smooth  nature,  and  does  not  fill  up 
any  interstices  or  leave  an  uneven  surface,  and  thus  the  shape 
of  the  article  is  preserved.  Consequently,  bolts  and  screws 
which  have  been  threaded  can  be  galvanised  without  the  necessity 
of  re-cutting  the  threads. 


380  SfflPS'  BOATS 

Another  advantage  is,  that  it  covers  every  portion  of  the  article 
and  penetrates  the  smallest  holes,  and  sherardises  them  without 
clogging  up.  The  surface  can  be  readily  polished  without  the 
zinc  being  rubbed  off. 

In  the  ordinary  hot  dipping  process,  the  iron  receives  a  thin 
coating  of  zinc,  which,  owing  to  its  brittle  nature,  may  crack, 
and  the  influence  of  the  damp  sea  air  will  thus  get  behind  the 
zinc  and  the  metal,  and  rusting  action  is  set  up.  The  sherardising 
process  largely  obviates  this  trouble. 

No  sudden  high  temperature  is  brought  on  the  material,  and 
the  gradual  cooling  down  subjects  the  iron  to  a  process  of 
annealing. 

The  whole  system  lends  itself  to  the  best  results  for  galvanising 
lifting  hooks,  screw  bolts,  nuts,  breasthooks,  thwart  knees,  angle 
lugs,  etc.,  used  in  the  construction  of  ships'  boats,  giving  a  highly 
finished  appearance  and  providing  a  permanent  and  satisfactory 
coating  for  the  prevention  of  corrosion. 

Electro-Galvanising. — The  process  of  electro-galvanising  is 
very  simple  and  effective,  provided  in  the  first  place  the  plant 
has  been  well  designed  and  constructed  by  engineers  of  experience, 
who  also  possess  both  a  practical  and  theoretical  knowledge  of 
the  subject. 

A  great  amount  of  power  and  labour  is  sometimes  lost 
through  the  installation  of  unsuitable  types  of  generators  and 
badly  constructed  tanks. 

There  are  several  advantages  associated  with  the  electro- 
proce.ss  wliich  account  for  its  extensive  use  in  the  United  States 
of  America  and  Great  Britain,  one  of  the  most  important  of 
which  is  that  throuf^hout  the  operation,  the  articles  to  be  galvanised 
are  not  subjected  to  f^aeat  heat,  and  the  physical  properties  of 
the  material  are,  therefore,  not  interfered  with.  This  is  a 
very  important  feature  in  connection  with  the  strength  of  lifting 
hooks,  davit  blocks,  and  other  gear  associated  with  life-saving 
appliances,  wliich  cannot  be  overlooked.  Another  advantage 
is  that,  during  the  whole  process  of  galvanising,  gases  are  not 
liberated,  but  this  lart^'ely  depends  upon  the  quality  of  the 
solution  used  in  the  electrolyte.  The  surface  of  the  zinc  deposit 
is  very  smooth,  evenly  distributed,  and  can  be  poUshed  if  con- 
sidered nocessary  for  a  particular  purpose. 

Tlie  wochis  o})erandi  for  <ralvanising  such  articles  as  are  used 
in  the  construction  of  shi})s'  boats  and  davit  gear,  is  briefly 
describiHl  as  follows  : — 

Th(^  surface  of  the  article  is  first  of  all  cleaned  with  gasoline 


r 
I 


METHODS  OF  GALVANISING 


381 


L 


to  remove  all  traces  of  greaae.  It  is  tlien  placed  in  a  potash  or 
acid  bath  to  eliminate  any  oil  that  may  be  left  ou  the  article, 
an<J  afterwards  thoroughly  washed  in  water.  It  may  be  further 
subjected  to  a  cleaning  process  from  a  sand  blast,  which  removes 
all  appearances  of  rust. 

The  procedure  of  cleaning  may  vary  in  different  eatablish- 
mente,  but  the  main  object  is  to  absolutely  clean  the  surface  of 
the  article  of  all  chemicals  to  ensure  that  the  zinc  will  adhere. 
The  article  is  then  placed  In  a  pickling  bath  containing  a  mixture 
of  hydrochloric  acid  and  water,  afterwards  thoroughly  washed, 
and  taken  to  the  tank  or  electrolyte  charged  with  the  zinc 
solution  for  plating. 

The  supply  of  current  to  the  electrolyte  ia  received  from 
generators  of  low  voltage,  which  enables  the  articles  to  be  handled 
by  the  operators  with  freedom  and  safety. 

Zinc  plates  or  anodes  are  suBpende4  to  the  anode  bai-s,  which 
are  connected  to  the  positive  pole  of  the  current  and  are  situated 
at  the  side  of  the  tardc. 

The  articles  to  be  galvanised  arc  totally  immersed  in  the 
solution,  but  suspended  from  tlie  cathode  bar  running  over  the 
centre  and  top  of  the  tank,  and  connected  to  the  negative  pole 
of  the  current. 

The  standard  solution  supphed  by  the  Galvanising  Corporation 
of  America,  Brooklyn,  N.Y.,  with  which  the  writer  has  had  some 
experience,  is  self-sustaining,  and  does  not  require  any  additions 
beyond  a  little  water  when  the  density  is  increased.  This  high 
standard  of  efficiency  for  any  solution  can  only  be  maintained 
if  the  plant  is  kept  free  from  leakage,  etc. 

The  amount  of  zinc  deposited  on  the  article  depends  on  the 
form  of  surface  to  be  coated.  An  irregular  surface  means  an 
uneven  distribution,  e.g.  an  article  which  has  been  screw-threaded, 
requires  to  be  left  in  the  plating  tank  a  longer  time  than  if  it 
were  a  plane  surface  ;  or  the  voltage  of  the  current  increased,  in 
order  that  the  zinc  deposit  may  reach  the  recesses  of  the  screw 
threads.  The  amount  of  zinc  deposited,  therefore,  depends  on 
the  number  of  ampere-hours  of  current  used. 

The  action  of  the  electric  current  is  to  decompose  the  solution, 
and  the  zinc  is  deposited  on  the  surface  of  the  article.  The 
solution  for  the  moment  has,  therefore,  lost  some  of  the  zinc  which 
it  originally  contained,  and  it  immediately  reacts  on  the  zdnc 
anodes  attached  to  the  positive  pole  of  the  electric  current 
received  from  the  generators,  so  that  the  solution  is  constantly 
and  automatically  kept  up  to  full  strength. 


382  SHIPS'  BOATS 

The  usual  thickness  of  the  galvanised  coating  is  about  half 
an  ounce  for  every  square  foot  of  surface. 

The  efficiency  of  the  operation  depends  largely  on  the  quality 
of  the  solution,  maintaining  pure  zinc  in  the  electrolyte  without 
mixing  with  gases  of  a  detrimental  nature,  and  depositing  the  same 
in  this  condition  on  the  surface  of  the  article.  It  is  also  essential 
for  the  solution  to  have  a  high  power  of  conductivity  in  order  to 
"  throw  in ''  the  zinc  to  the  innermost  recesses  in  ihe  article  to 
be  galvanised,  so  that  the  surface  may  remain  smooth,  uniform, 
and  not  become  porous  or  spongy. 

After  the  articles  have  been  suspended  in  the  solution  for  the 
required  time,  they  are  taken  out  of  the  plating  tank,  placed  in 
the  hot  water  bath,  and  then  stacked  for  drying. 

SECTION  D.— PAINTING 

Keference  has  already  been  made  in  Section  A  of  Part  IV.  to 
the  importance  of  coating  the  faying  surfaces  of  all  material  with 
paint  of  good  quality,  as  progress  is  made  on  the  construction  of 
wooden  boats. 

Some  shipowners  demand  that  the  boat  must  be  covered  with 
two  good  soaking  coats  of  boiled  linseed  oil,  and  allowed  to  dry 
before  the  usual  number  of  coats  of  paint  are  applied.  The 
inclusion  of  such  a  clause  in  a  specification  can  be  well  recom- 
mended, as  it  extends  the  life  of  a  boat  and  increases  the  resisting 
quabties  of  the  planking  to  the  effects  of  the  weather  and  the 
changes  of  atmosphere. 

As  each  particular  detail  of  the  combination  in  the  frame  is 
worked,  the  faying  surfaces  should  be  thickly  covered  with  good 
white-lead  paint,  particularly  in  way  of  the  hog  piece,  keel, 
deadwoods,  apron,  and  stem  or  stempost.  The  landing  edges 
of  the  planks,  when  the  clinker  method  is  being  used,  and  the 
various  details  of  the  box  gunwale  and  capping  piece,  should  also 
be  painted  before  they  are  secured  in  position. 

The  most  important  protective  covering  the  boat  receives 
is  that  which  is  appUed  to  the  inside  of  the  planking  before  the 
timbers  are  worked.  This  should  be  undertaken  so  that  the 
paint  has  an  opportunity  to  dry  over  the  week-end.  There  is  a 
tendency  with  many  of  the  boatbuilders  to  mix  too  large  a  pro- 
portion of  dryers  with  the  paint  in  order  to  allow  the  work  of 
timberinii;  to  proceed  with  rapidity,  and  in  so  doing  the  object 
in  applying  this  first  coat  is  defeated. 

The  instructions  issued  by  the  Board  of  Trade  demand  three 


^H   coats  of 
^P    twocoal4 


PAINTING 


383 


I 


coals  of  the  best  white-lead  paint  to  be  applied  on  the  outside  and 
ttvo  coai^  on  the  inside.  Care  should  be  taken  to  let  each  individual 
coat  dry  before  the  second  or  third  coat  is  applied.  Attention 
should  be  paid  by  the  inspector  to  see  that  the  second  coat  of 
paint  is  applied  to  the  planking  and  timbers  before  the  buoyancy 
air-cases  are  inserted,  and  the  tank  cleadinj;  secured  ui  position. 

Where  lifeboats  have  been  constructed  of  material  unsuitable 
for  the  trade  in  which  the  vessel  is  engaged,  and  where  the  heat  of 
the  tropics  has  a  detrimental  effect  on  the  planking,  it  has  some- 
tiniBH  become  necessary  to  thickly  coat  the  inside  of  the  plank- 
ing with  a  bitumastic  enamel,  as  the  plastic  nature  of  this 
composition  enables  the  seams  to  preserve  a  watertight  joint. 

I'he  necessity  for  resorting  Ut  this  method  should  never  arise 
if  vessels  engaged  in  tropical  waters  have  their  boats  constructed 
of  teak,  mahogany,  or  steel,  and  the  material  is  well  seasoned. 

Where  boats  are  subjected  to  great  beat,  or  altematii^  con- 
ditions of  heat  and  cold,  it  is  absolutely  necessary  for  the  material 
to  be  thoroughly  seasoned,  and  it  cannot  be  expected  that  the  paint 
will  cover  up  a  "multitude  of  sins."  The  necessity  for  the 
application  of  bitumastic  enamel  on  wooden  boats  should  never 
arise  if  ordinary  precautions  are  taken,  and  the  authorities  demand 
the  most  suitable  woods  to  be  used  in  the  construction  of  boats, 
having  in  view  the  particular  service  in  which  they  will  be 
engaged.  The  responsibihty  of  the  shipowner  should  not  be 
limited  in  this  respect. 

Paint  is  made  up  from  five  constituents,  viz.,  a  base,  vehicle, 
drier,  solvent,  and  a  colouring  pigment. 

The  base  is  the  main  substance  which  gives  the  necessary 
body  and  covering  power. 

The  vehicle  is  a  semi-liquid  which  when  combined  with  the 
base  allows  it  to  be  spread  on  the  surface  of  the  material  with  a 
brush,  in  a  thin  and  sufficient  quantity. 

The  base  and  the  vehicle  are  the  two  important  essentials. 

In  order  to  permit  the  base  to  dry  with  reasonable  rapidity 
and  maintain  the  proper  degree  of  hardness,  driers  are  added  to 
the  mixture. 

To  give  the  required  thinning  power  and  freeness  to  flow,  a 
solvent  must  also  be  included. 

The  'pigment  is  simply  added  to  give  the  necessary  colour  for 
decorative  purposes. 

It  is  necessary  to  understand  the  nature  of  these  constituents 
when  mixing  up  the  paint  for  the  purpose  required,  so  as  to  obtain 
the  beat  results. 


384  SHIPS'  BOATS 

The  presence  of  resin  causes  paint  to  crack  after  a  time  of 
exposure,  while  that  of  driers  also  produces  the  same  effect. 

Turps  oxidises  on  exposure  to  air,  becomes  converted  into  a 
resinous  substance,  and  has  little  of  the  weather-resisting  pro- 
perties of  oil.  It  should  therefore  be  used  on  external  work  only 
in  sufficient  quantity  to  make  the  paint  flow  readily  from  the 
brush. 

The  use  of  naphtha  should  be  strongly  condenmed,  and  every 
care  must  be  taken  to  prevent  the  excessive  application  of  large 
quantities  of  driers. 

White-lead  is  the  most  common  base  that  is  used  for  paint 
in  boatbuilding.  It  is  usually  prepared  in  the  form  of  powder 
and  combined  with  refined  linseed  oil.  It  tends  to  become 
darker  when  exposed  to  the  sea  air  and  changes  in  composition. 
It  has  the  disadvantage  of  possessing  poisonous  qualities. 

Zinc  white,  or  oxide  of  zinc,  is  pure  white  in  colour,  possesses 
greater  covering  power  than  white-lead,  does  not  affect  the  linseed 
oil  in  the  same  way  as  the  latter ;  is  non-poisonous,  and  is  not 
affected  by  the  sea  air. 

Linseed  oil  is  produced  from  the  ripe  flax  seed  by  compression. 
It  is  pale  in  colour,  and  best  used  in  association  with  a  base  for 
internal  work. 

In  its  raw  state  it  becomes  oxidised  when  exposed  to  the 
weather  and  dries  very  slowly.  Boiled  linseed  oil  dries  much 
quicker  than  tlie  raw  material,  and  its  weather-resisting  qualities 
are  greatly  increased  by  the  boiling  process. 

Spiritii  of  turpentine  is  the  only  solvent  that  is  used  with  paint 
when  mixed  with  oil,  and  then  only  to  a  Umited  degree,  and  in 
sufficient  quantity  to  allow  tlie  paint  to  be  easily  worked  with  a 
brush.  There  is  very  little  power  in  the  turpentine  to  resist  the 
effect  of  the  weather  when  exposed  to  the  sea  air,  as  it  oxidises 
and  eventually  perishes.  It  is  obtained  as  a  result  of  distilling 
the  crude  turpentine  secured  from  the  pine  and  larch  trees,  the 
residuum  beini;  resin. 

The  followini^  compositions  are  freely  used,  and  can  be. recom- 
mended for  all  work  in  connection  with  the  construction  of 
ships'  boats  : — 

TJie  Mercantile  Marine  Sermce. 

Best  white-lead    .      , 1  cwt. 

Patent  driers 14  lbs. 

Raw  linseed  oil 3J  galls. 

Spirits  of  turpentine 1  quart. 


PAINTING  385 

The  British  AdmiraUy. 
Great  Paint — 

Genuine  white-lead 73  lbs. 

Ordinary  black 8f^  lbs. 

Turpentine  substitute 6  pints. 

Raw  linseed  oil 16  pints. 

Marine  driers 7  lbs. 

White  Paint— 

Genuine  white- lead    .......  84  lbs. 

Marine  driers 7  lbs. 

Raw  linseed  oil 13  pints. 

Turpentine  substitute 6J  pints. 

Varnishes  are  divided  into  two  classes,  oil  and  spirit.  The 
former  is  used  for  outdoor  work,  where  the  material  is  exposed 
to  the  effect  of  the  weather,  and  the  latter  should  only  be 
used  for  interiors. 

The  gums,  which  are  obtained  by  the  process  of  tapping  certain 
trees,  mostly  pines,  contain  two  substances,  an  oil,  which  after 
treatment  by  evaporation  leaves  a  residuum,  called  resin.  The 
resisting  property  is  the  resin  itself ;  hard  resin  is  bright,  but 
brittle,  while  the  soft  resin  is  more  elastic,  due  to  the  proportion 
of  oil  it  contains. 

Amber  and  copal  are  two  good  oil  varnishes ;  the  former  is 
foimd  around  the  Baltic,  and  the  latter  obtained  from  the  East 
and  West  Indies. 

Lac  varnish  is  a  spirit  varnish  and  cannot  withstand  the  effect 
of  rain  or  the  action  of  the  sun.  Resin  varnish  must  be 
avoided  altogether,  being  a  production  from  turpentine,  which 
quickly[|cracks  and  peels  off  when  exposed  to  the  weather. 

Oil  varnishes  are  usually  made  from  a  particular  resin, 
associated  with  linseed  oil  and  thinned  with  turpentine.  Spirit 
varnish  is  composed  of  another  quality  of  resin  which  is  dissolved 
in  methylated  spirits. 

Immediately  the  stem  and  stempost  are  erected,  it  is  a  great 
advantage  to  coat  them  with  an  oil  varnish  as  a  protection  from 
the  weather,  and  to  prevent  the  oak  from  opening  out  during 
the  period  of  construction. 

It  is  usual  to  varnish  the  outside  of  the  upper  strakes,  the 
rubbers,  and  the  gunwales,  with  two  coats  of  good  oil  varnish. 

Every  portion  of  the  boat  should  be  painted,  particularly 
those  portions  which  are  not  exposed  to  view,  e.g.  the  underside 

2  c 


386  SHIPS'  BOATS 

of  all  thwarts  and  side  benches.  The  extra  ten  minutes  spent 
on  the  operation  of  painting  makes  all  the  difference  to  the 
appearance  of  a  boat. 

Putty  should  be  very  sparingly  used,  and  its  application 
practically  confined  to  the  keel  seam  and  hoodedends  of  planks. 
An  inferior  quahty  of  putty  is  made  from  whiting  and  oil,  which 
very  quickly  deteriorates  when  exposed  to  the  weather.  It 
should,  therefore,  be  composed  of  the  best  white-lead  with  boiled 
Unseed  oil,  and  worked  into  the  seams  with  a  wooden  tool  shaped 
like  a  pencil. 

SECTION  E.— REPAIRS  AND  MAINTENANCE 

OF  BOATS 

When  lifeboats  have  been  constructed  in  accordance  with  a  good 
specification,  and  the  workmanship,  together  with  the  material, 
are  of  a  high  standard,  the  necessity  for  repairs  will  be  practically 
confined  to  cases  of  actual  damage,  instead  of  the  constant  process 
of  patching  up,  which  is  bound  to  occur  when  boats  are  con- 
structed to  the  ideas  of  persons  who  are  not  controlled  by  standard 
and  detailed  regulations. 

The  action  of  the  British  Board  of  Trade  acting  in  co-operation 
with  the  boatbuilders  throughout  the  United  Kingdom,  including 
the  Boat,  Yacht,  and  AUied  Trades  Association,  in  maintaining  a 
standard  specification  with  full  details  of  scantlings,  etc.,  is 
greatly  to  be  commended,  and  will  obviate  the  necessity  of  boats 
coming  into  the  hands  of  the  repairers  with  the  frequency  which 
has  hitherto  been  associated  with  boatbuilding. 

The  responsibility  for  upkeep  will  now  rest  almost  entirely 
with  the  ship's  officers,  and  if  a  little  attention  and  oversight 
are  paid  to  the  boats  when  in  regular  service  on  a  vessel,  the 
result  will  be  a  considerable  saving  to  the  shipowner. 

The  initial  trouble  which  has  boon  responsible  for  many  leaky 
boats,  was  originally  caused  through  the  use  of  unseasoned 
material  and  defective  plank  seams. 

The  practice  of  caulking  a  thread  of  cotton  into  all  the  plank 
seams  of  a  clinker-built  boat  should  be  discouraged.  It  naturally 
follows  that  le.ss  care  will  be  exercised  by  the  workman  during 
the  important  process  of  fitting  the  plank  landings,  because  he 
relies  on  the  cauUdng  to  make  good  what  he  has  omitted  during 
the  progress  of  constniction.  Even  if  the  thread  of  cotton  were 
inserted  between  the  landings  before  t^he  fastenings  were  hardened 
up,  it  would  have  some  reason  to  commend  itself,  but  it  is  the 


REPAIRS  AND  MAINTENANCE  OF  BOATS      387 

writer's  (ipinion,  that  it  is  to  the  advantage  of  the  boat  if  the 
,ma  iire  fitted  close  toj^etlier  without  the  insertion  of  any 
parking,  beyond  a  good  thick  coat  of  paint,  or  the  apphcatiun 
of  "  blair." 

It  inevitably  follows,  even  when  the  seams  are  puttied,  that 
the  cotton  will  begin  to  swell  after  a  time,  and  bring  an  uudue 
stress  on  the  plank  fastenings,  with  the  inevitable  consequence, 
sooner  or  later,  that  the  planks  will  split  along  the  landing. 
This  trouble  has  been  a  common  nccurrencp,  and  responsible  for 
much  dissatisfaction  among  shipowners. 

When  considering  the  question  of  repairs,  we  should  keep  in 
mind  the  necessity  t^>  avoid  taking  out  a  plank  except  when  it 
is  absolutely  essential. 

If  the  seams  or  landings  of  the  planks  are  generally  leaky, 
they  should  be  lightly  caidked,  because  the  material  will  be  seasoned 
after  the  boat  has  been  exposed  on  the  boat  deck  of  a  vessel. 
The  plank  and  timber  fastenings  should  be  hardened  up,  and  the 
seams  well  puttied  inside  and  out.  Instead  of  the  light  caulk, 
pouring  in  a  ajliition  of  Stockholm  tar,  bitumastic  enamel,  marine 
glue,  or  other  such  elastic  solution,  mixed  with  a  httle  flock  or 
thinly  shredded  oakum,  between  the  landing  edges,  will  overcome 
the  difficulty.  The  drawback  to  the  use  of  a  bitumastic  enamel 
is  foimd  when  the  heat  of  the  sun  causes  the  solution  to  run 
through  the  landings  and  discolour  the  paint  on  the  outside  of  the 
boat. 

When  a  lifeboat  comes  in  for  periodical  survey  and  overhaul, 
one  naturally  looks  at  particular  portions  of  the  structure  for 
signs  of  trouble.  The  butts  of  the  planking  should  be  carefiUIy 
examined,  particularly  at  the  hooded  ends.  The  keel  seams, 
the  planks  and  landings  in  way  of  the  stowage  chocks,  the  con- 
dition of  the  stem  and  stempost  scarphs  at  the  keel,  the  lifting 
hooks,  keel  plates,  and  deadwoods;  should  be  carefully  inspected. 
Attention  should  be  paid  to  any  signs  of  broken  timbers. 

If  the  boat  has  been  thickly  coated  with  paint,  this  should  be 
burnt  oS,  but  in  any  case  the  paint  sliould  be  scraped  off  the 
plank  scarphs  or  butts. 

It  is  usually  foimd  necessary  to  strip  out  the  cotton  from  the 
hooded  ends  of  the  planks,  refast«n  with  a  row  of  \nans  screws, 
recaulk,  and  till  the  seams  with  putty. 
The  keel  seam  is  usually  re-caulkcd. 
Broken  timbers  are  best  dealt  with  by  fi^ 
timbers  adjacent  to  the  old  ones,  and  in  one  lein^" 
piece,  and  running  them  up  as  high  above  th«^ 


388 


SHIPS'  BOATS 


seats  will  allow,  care  being  exercised  not  to  split  tiie  plank 
landings. 

Split  planks  must  be  taken  out  if  situated  below  ihe  binding 
strake,  but  the  operation  should  only  be  tuidertaken  by  a  boat- 
builder,  otherwise,  inexperienced  hands  will  do  more  barm  than 
good  to  the  adjacent  planks. 

A  temporary  repair  can  be  made  by  fitting  a  doubling  on  the 
inside  of  the  plank  if  the  damage  is  not  extensive,  or  by  securing 
an  outside  doubling  as  shown  in  Fig.  222,  and  well  bedding  the 
f a}dng  surfaces  with  thick  white-lead  paint. 

Sheet  lead  tacked  on  the  outside  of  the  planking  will  keep  the 
boat  tight  until  proper  repairs  can  be  undertaken  in  port. 


m 


M 


k 


•  O  ' 


o  : 


/?0(/s///x{P 


o  : 


■  o 


.  o  . 


suvr/fffi 


TfMBe/f 


¥ 


V 


J>OU8l/flK 


ELEVATION 


SECTION 


Fig.  222. — Botails  of  doubling  to  a  damaged  plank. 


Any  disturbance  to  the  binding  strake  should  be  avoided, 
and  local  attention  given  to  the  damage  rather  than  interfere 
with  the  strake  as  a  whole. 

Broken  gunwales  of  the  sohd  type  are  not  infrequent,  brought 
about  through  the  lack  of  proper  incorporation  witii  the  timbers, 
and  the  lack  of  a  good  stout  rope  fender.  To  take  out  the  full 
length  of  gunwale  is  a  difficult  operation,  and  if  the  damage 
is  confined  to  one  place,  a  compromise  may  be  effected  by 
scarphing  a  new  piece  into  the  main  portion  of  the  original 
gunwale.  The  scarph  should  be  at  least  12  in.  in  length,  with  a 
stout  doubhng  piece  fitted  under  the  gunwale,  extending  for  a 
lengtli  of  2  ft.,  and  secured  as  illustrated  in  Fig.  223  a. 

The  United  States  Steamboat  Inspection  Service  permits  new 
])oats  to  be  constnictc^d  with  gunwales  made  in  two  lengt'hs. 


"REPAIKS  and  maintenance  of  boats      389 

being  scarphed  with  a  good  long  bevel  or  lip,  and  stiflEened  on  the 
underside  by  a  piece  of  gunwale  material  at  least  2  ft.  in  length, 
1 J  in.  thick,  and  the  width  of  the  gunwale. 

If  the  plank  edges  of  a  clinker-built  boat  are  damaged  in  way 
of  the  stowing  chocks,  and  have  become  worn  through  the  con- 
tinual rubbing  when  settling  the  boat  into  position  to  fix  the 
gripes,  compensation  can  be  given  by  fitting  pad  pieces  from  the 


UPPr^  SrRAKE 


A. -DETAIL   or  GUNWALE    SCARPH 


B.  -REPAIR  TO   DAMAGED  KEEL  — 


I,        ^  •!  ,| 

!•  \  f(££iSOA/\ 

!;  FfiuAfG  V  8 


r/M3£W 


f  y!^/////o|/^//jY////j^^ 


M 


ff£eL       :l 


c "  w T    •: 

\      cfOverAfL  ^/ic£    I    I, 


^/^<?/vP4.ar£ 


FlO.  223. 


keel  to  the  bilge  for  a  length  of  12  to  15  in.,  and  the  stowage 
chocks  made  to  suit. 

One  usually  finds  plenty  of  paint  on  a  boat  after  a  few  years' 
service,  except  in  way  of  the  chocks,  the  position  where  the  need 
for  protection  is  the  greatest. 

Occasionally  a  stem  or  stempost  becomes  damaged,  and  can 
be  repaired  without  the  necessity  of  removing  the  associated 
combinations,  by  backing  out  the  apron  and  deadwood  fastenings, 
scarphing  in  a  new  stem  and  stempost-piece,  and  fitting  an 
additional  breasthook  in  way  of  the  scarph. 

Local  damage  to  a  keel  as  a  result  of  fouling  some  obstruction 
when  launching  the  boat,  or  the  opening  out  of  a  defective  knot 


390  SHIPS'  BOATS 

when  the  material  has  become  seasoned,  causing  the  boat  to  sag, 
may  often  occur.  Fig.  223  b  shows  how  the  local  weakness  may  be 
remedied,  by  fitting  an  iron  plate  xmder  the  keel,  of  sufficient 
length  to  take  a  nimiber  of  long  screw  bolts,  having  their  nuts 
hove  up  on  stout  washers  fitted  to  the  keelson. 

The  United  States  regulations  insist  that  lifeboats  shall  be 
stripped,  cleaned,  thoroughly  overhauled,  and  painted  at  least 
once  in  every  year. 

Lifeboats  which  form  part  of  the  statutory  equipment  of  a 
passenger  vessel  are  periodically  inspected  by  surveyors  of  the 
Board  of  Trade,  who  are  also  responsible  for  the  survey  of  the 
steamer. 

The  life-saving  aj)pliance8  of  all  cargo  vessels  are  liable  to  be 
inspected  by  the  surveyors,  whenever  they  come  into  a  British 
port,  whether  the  vessel  is  British  or  foreign-owned.  It  is 
considered  that  the  present  available  staff  of  the  Board  of  Trade 
is  insufficient  for  the  amount  of  oversight  that  is  necessary  for 
carrying  out  a  proper  and  systematic  survey. 

Much  of  the  loose  talk  which  one  occasionally  hears  about  the 
condition  of  ships'  boats,  is  largely  the  result  of  a  poor  system 
of  maintaining  efficiency  and  periodical  inspection  by  the  officers 
who  are  held  responsible  for  the  upkeep  of  the  apparatus. 

It  is  also  difficult  to  maintain  the  constant  interest  of  the  crew 
on  a  cargo  vessel  in  the  condition  of  the  boats  and  equipment, 
owing  to  the  brevity  of  their  stay  on  a  j)articular  ship.  The 
system  of  signing  (m  crews  for  each  voyage  has  its  disadvantage 
in  this  respect. 

If  only  ordinary  care  is  taken  to  maintain  the  boats  in  a  clean 
condition ;  the  davits,  with  their  associated  gear,  periodically 
worked,  and  the  crews  trained  in  the  use  and  management  of  the 
life-saving  equipment,  the  need  for  a  more  constant  inspection 
would  not  be  so  necessary. 

The  buoyancv-tanks  should  be  removed  at  least  every  twelve 
months,  and  the  planking  of  the  boat  thoroughly  coated  with 
paint  of  a  good  quality. 

When  the  boats  come  in  for  repair  or  annual  survey,  oppor- 
tunity should  be  taken  to  lemove  the  buoyancy- tanks  and  pass 
them  through  the  water- tank  for  the  usual  test. 


PART   VIII 

FIRE  AND  BOAT  DRILLS 

In  the  foregoing  chapters  the  question  of  the  construction  and 
equipment  of  ships'  boats  has  been  considered  in  some  detail, 
but  it  is  obvious  that  in  addition  to  the  high  standard  of  con- 
struction and  the  efficient  provision  of  suitable  life-saving 
apparatus,  it  is  very  necessary  that  the  officers  and  crew  of 
passenger  and  cargo  vessels  shall  be  thoroughly  trained  in  the 
proper  handUng  of  the  Hfeboats  and  rafts. 

The  evidence  of  excited  passengers,  during  the  proceedings 
of  official  inquiries  into  the  loss  of  merchant  vessels,  as  a  result 
of  coUisioii,  or  explosion  from  torpedo  attack,  has  often  given  a 
wrong  impression  to  the  "  man  in  the  street "  as  to  what  really 
took  place  during  the  operation  of  launching,  so  as  to  cause  the 
boats  to  become  unsea worthy. 

The  loss  of  the  steamships  Titanic,  Lasitania,  Empress  of 
Irekvnd,  and  FaUihd,  together  with  their  valuable  complement  of 
passengers  and  crews,  caused  the  interest  of  the  whole  world  to  be 
centred  on  this  all- important  question  of  life-saving  appliances. 

The  subject  of  an  adequate  and  compulsory  training  for 
seamen  in  the  management  and  saihng  of  lifeboats,  was  keenly 
discussed  during  various  inquiries,  and  the  question  has  always 
been  one  of  interesting  debate  among  ships'  officers,  especially  in 
view  of  the  conditions  under  which  the  crews  of  the  Mercantile 
Marine  Service  are  signed  on. 

In  the  majority  of  cases,  the  men  do  not  join  the  ship  until 
just  before  the  vessel  sails,  and  they  may  only  remain  on  that 
vessel  for  the  one  voyage.  There  are,  of  course,  exceptions  to 
the  general  procedure,  where  passenger  vessels  are  running  con- 
stantly on  a  fixed  route,  but,  generally  speaking,  there  is  very 
little  incentive  for  seamen  to  specialise  in  this  particular  and 
important  branch  of  their  duties. 

With  an  ordinary  tramp  steamer  carrying  cargo,  and  without 
passengers,  the  majority  of  the  crew  are  probably  making  only 


392  SHIPS'  BOATS 

one  voyage  in  the  vessel,  consequently,  they  are  not  keen  to 
take  a  special  interest  in  the  upkeep  of  the  life-saving  equipment. 
Without  the  responsibility  of  making  any  special  arrangements  for 
the  safety  of  passengers,  the  interest  of  the  officers  and  crew  in 
making  suitable  provision  for  their  own  safety,  has  often  been 
lacking ;  this  is  a  matter  of  some  surprise  to  those  whose  duty 
it  is  to  see  that  the  regulations  are  carried  out.  The  recent 
submarine  menace  made  a  considerable  difference  to  this  feeling 
of  apathy  so  often  exhibited ;  but  it  was  surprising  how  quickly  the 
seamen  became  used  to  their  surroundings,  and  their  attitude 
resolved  itself  into  a  condition  of "  familiarity  breeding  contempt.'* 

Various  proposals  have  been  made  from  time  to  time  to  create 
means  for  giving  proper  training  and  instruction  to  seamen, 
before  they  should  be  allowed  to  undertake  the  responsibility  of 
managing  ships'  boats  and  vessels'  life-saving  equipment;  this 
phase  of  the  subject  is  outside  the  intended  scope  of  the  present 
treatise. 

The  importance  of  the  matter  has  been  carefully  discussed 
by  various  authorities,  and  in  the  Report  of  the  Merchant 
Shipping  Advisory  Committee  of  1914,  the  question  of  the  manning 
of  the  boats  was  considered  by  the  sub-committee  dealing  with 
the  subject  of  the  type  and  construction  of  open  lifeboats,  and  the 
following  resolution  was  approved  by  the  majority  : — 

"  That  the  effective  manning  of  all  the  boats  carried  on 
"  passenger  and  emigrant  vessels  can  only  be  secured  by  the 
"  training  and  organising  of  the  crew  as  a  whole.  If  the  crew 
**  as  a  whole  be  so  trained  and  organised,  the  boats  can  be 
**  effectively  manned  if  there  are  two  efficient  boat  hands  carried 
**  for  each  of  the  boats  carried  under  the  davits,  or  immediately 
"  available  for  attachment  to  the  davits.  Facilities  should  be 
**  given  to  enable  all  hands  to  prove  their  competency  as  efficient 
**  boat  hands.'' 

The  committee  further  considered,  that  if  lascars  could  be 
trained  as  efficient  boat  hands  they  might  be  accepted  as  equal 
to  white  boat  hands,  provided  that  an  officer  or  petty  officer  was 
present  at  the  launching  of  each  boat,  to  communicate  the 
necessary  orders  to  them. 

It  was  uenerallv  considered  bv  the  committee  that  the  efficient 
training  of  passengers  to  take  part  in  the  boat  drill  was  impossible, 
and  that  the  safety  of  the  passengers  would  be  more  effectively 
secured  by  tlie  training  and  organisation  of  the  members  of  the 
crew  in  their  several  duties,  so  that  they  could  take  charge  of  the 
passengers  and  direct  them  to  the  boats  in  a  prompt  and  orderly 


FIRE  AND  BOAT  DRILLS 


393 


maimer.  It  is  thought  by  thd  writer,  however,  that  once,  at 
least,  on  every  oversea  trip,  the  passengers  ought  to  be  asked  to 
perform  life-jacket  and  boat  drill. 

The  International  Convention  on  Safety  of  Life  at  Sea  have 
formulated  regulations  in  connection  with  the  manning  of 
lifeboats  and  rafts  for  passenger  vessels. 

The  following  notes  have  been  taken  from  the  Merchant 
Shipping  (Convention)  Act,  1914  : — 

There  nmst  be,  for  each  boat  or  raft  required,  a  minimum 
number  of  certified  Ufeboatmen.  The  allocation  of  the  certified 
lifeboatmen  to  each  boat  and  raft  remains  within  the  discretion 
of  the  master,  according  to  the  circumstances. 

In  order  to  obtain  the  special  hfeboatman's  certificate,  the 
applicant  must  prove  that  he  has  been  trained  in  all  the  operations 
connected  with  launching  hfeboats  and  the  use  of  oars,  that  he  is 
acquainted  with  the  practical  handUng  of  the  boats  themselves, 
and  further,  that  he  is  capable  of  imderstanding  and  answering 
the  orders  relative  to  lifeboat  service. 

An  officer,  petty  officer,  or  seaman,  must  be  placed  in  charge 
of  each  boat  or  pontoon  raft,  and  have  in  his  possession  the 
names  of  its  crew,  and  must  see  that  the  men  placed  under  his 
orders  are  acquainted  with  their  several  duties  and  stations. 

A  man  capable  of  working  the  motor  must  be  assigned  to  each 
motor  boat. 

One  or  more  officers  must  be  assigned  to  see  that  all  the  boats, 
pontoon  rafts  or  other  Ufe-saving  appUances  are  at  all  times 
ready  for  use. 

The  minimum  number  of  lifeboatmen  allocated  to  each 
lifeboat  or  raft  is  dependent  on  the  carrying  capacity  of  the  latter, 
and  is  as  follows  :— 


Certified  capacity  of  boat  or  raft. 


Minimum  number  of 
certified  lifeboatmen. 


Lcsti  than  61  persons     . 
From    61  to    85  persons 
86  to  110 
„      111  to  160 
161  to  210 


>» 


»t 


»» 


>» 


3 
4 
5 
6 

7 


And  thereafter,  one  additional  certified  lifeboatman  for  each 
additional  50  persons. 

Musters  of  the  crew  at  their  boat  stations,  followed  by  boat 
drills,  must  be  held  at  least  once  a  fortnight,  either  in  port  or  at 


2"  394  SfflPS"  BOATS 

{  sea.     An  entry  being  made  in  the  official  log  book  of  these  drill 

or  of  the  reasons  why  they  could  not  be  held.  ^ 

Different  groups  of  boats  are  to  be  used  in  turn  at  successi^ 
boat  drills.  The  drills  and  inspections  to  be  so  arranged  that  tl 
crew  thoroughly  understand  and  are  practised  in  the  duties  the 
have  to  perform,  and  that  all  the  boats  and  pontoon  rafts  on  tl 
ship  with  the  gear  appertaining  to  them  are  always  ready  f( 

4  1  immediate  use. 

i!  The  muster  list  is  to  assign  duties  to  the  different  members  i 

the  crew  in  connection  with — 

(a)  The  closing  of  the  watertight  doors,  valves,  etc. 

li  (b)  The  equipment  of  the  boats  and  rafts  generally. 

(c)  The  launching  of  the  boats  attached  to  davits. 

(d)  The  general  prepamtion  of  the  other  boats  and  the  ponton 
rafts. 

(e)  The  muster  of  the  passengers. 
(/)  The  extinction  of  fire. 
The  same  nmster  list  is  also  to  assign  certain  duties  to  tl 

members  of  the  stewards'  department,  to  enable  them  to  contr< 
the  passengers  at  a  time  of  emergency.     These  duties  are  i 
follows : — 
*  (a)  Warning  the  passengers. 

(6)  Seeing  that  the  passenger's  are  dressed  and  put  on  the 

life-jackets  in  a  proper  manner, 
(c)  Assembhng  the  passengers. 
I  (d)  Keeping  order  in  the  passages  and  on  the  stairways,  an 

1  generally  controlling  the  movements  of  the  passengers. 

The  regulations  fornmlatcd  by  the  Convention  relative  to  tt 
j  manning  of  boats  and  the  necessity  for  certified  lifeboatme 

j  have  akeady  been  embodied  in  the  General  Rules  issued  by  tt 

-  United  States  of  America,  wherein  it  is  stated  : — • 

j  "By  *  certified  lifeboatnian '  is  meant  any  member  of  tl 

crew  who  holds  a  certificate  of  efficiency  issued  under  ti 
authority  of  the  Secretary  of  Commerce. 

"  In  order  to  obtain  the  special  lifeboatman's  certificate  th 
applicant  must  prove  to  the  satisfaction  of  an  officer  designate 
by  the  Secretary  of  Commerce  that  he  has  been  trained  in  a 
the  operations  connected  with  launching  lifeboats  and  th 
use  of  oars  ;  that  he  is  acquainted  with  the  practical  handlin 
of  the  boats  themselves ;  and  further,  that  he  is  capable  ( 
understanding  the  orders  relative  to  lifeboat  service." 
When  the  crew  joins  a  British  ship,  one  of  the  first  duti< 
devolving  upon  the  executive  staff  is  the  allocation  of  evei 


^^1^  FlllE  AND  BOAT  DRILLS  395 

member  of  tUe  ship's  compauj  to  one  or  otJier  of  the  boata.  In 
order  to  make  this  system  very  effective,  moat  of  the 
passenger  steamship  companies  arrange  for  each  of  the  deck, 
stokehold,  and  steward  departments,  beiuj;  furnished  with  a 
badge,  bearing;  the  number  of  the  boat  to  which  he  belongs. 

A  miistcr  list  U  then  prepared,  which  shows  clearly  the  names 
of  all  the  crew,  and  details  their  various  duties  connected  with 
the  fire  and  boat  drills,  giving  the  particular  boat  to  which  they 
are  attached. 

A  copy  of  this  Hst  is  placed  iu  a  prominent  position  in  the 
various  departments,  to  assist  all  tlie  niembois  of  the  crew  to 
become  familiar  with  theii'  various  duties,  and  to  enable  them 
to  quickly  pick  up  their  positions  in  case  of  disaster,  and  to 
prevent  panic  among  the  passengers. 

Several  of  the  leading  British  shipping  companies  have  been 
good  enough  to  supply  the  writer  with  specimen  muster  lists, 
giving  in  full  detail  the  various  duties  which  are  allocated  to  the 
officers  and  ciews,  but  no  usefid  purpose  will  be  served  in  repro- 
ducing a  list  issued  by  any  particular  company.  Each  of  these 
lists  may  differ  in  detail,  but  in  substance  they  are  i>ractically 
the  same. 

The  following  notes  will  fjive  tlie  readLT  a  general  idea  of  the 
various  duties  allotted  to  the  memburs  of  the  crew. 

Usually  a  plan  of  the  boat  stowage  is  indicated  on  the  muster 
list,  every  boat  being  numbered  with  .large  and  distinct  figures, 
odd  numbers  being  on  the  starboard,  even  numbers  on  the  port 
side.  OroupB  of  boats,  boata  stowed  one  above  the  other,  are 
also  lettered  A,  B,  C,  etc.,  in  addition  to  their  number. 

Under  each  number  and  letter  are  shown  the  names  of  the 
various  members  of  the  crew  who  have  been  allocated  to  that 
particular  boat. 

Various  officers  are  selected  to  control  the  different  groups  of 
boats,  and  each  boat's  crew  is  divided  into  two  companie,s,  one 
consisting  of  six  "  station  men,"  who  take  the  following 
positions  : — 

No.  1 Lower  forward  fall. 

No.  2 Clear  away  fall. 

No.  3 Lower  after  (all. 

No.  4 t'lear  away  fall. 

Nos.  5  and  6   .     .     .  .in  boat   to  attend  to   re;; 

leasing  gear  (one  forward 
and  one  aft) 


396  SHIPS'  BOATS 

the  roinaiuder  are  "  spare  nieu,"  and  will  attend  to  any  duties 
which  may  be  given  them  by  the  officer  in  charge. 

The  stewards  are  generally  responsible  for  the  provisioning  of 
the  boats,  and  acting  in  conjunction  with  the  purser  and  chief 
stewaid,  control  the  passengers  below  decks  and  assemble  them 
in  proper  order  at  the  various  boat  stations. 

"  Man  overboard  "  is  usually  notified  by  continuous  short 
blasts  on  the  steam  whistle.  .  The  emergency  boats  situated 
nearest  to  the  bridge,  one  on  each  side  of  the  vessel,  are  kept 
constantly  rigged  outboard  in  the  davits,  ready  to  be  released 
at  a  moment's  notite,  with  special  faciUties  provided  for  quickly 
getting  into  the  boat,  usually  by  fitting  a  net  or  rope  ladders 
between  the  deck  and  boats.  Immediately  the  signal  is  given, 
tlie  watch  on  deck  should  at  once  man  the  lee  emergency  boat. 
The  officer  of  the  watch  is  responsible  for  these  boats  being  at  all 
times  ready  for  use. 

On  the  fire  alarm  being  sounded,  or  the  order  "  Fire  Stations  " 
given,  it  is  usual  for  the  junior  officer  on  watch  to  immediately 
proceed  to  the  seat  of  the  fire,  collect  the  watch  of  seamen  and 
other  available  men,  and  employ  them  to  extinguish  the  fire.  The 
second  ofiicer  remains  on  the  bridge,  the  chief  officer  being  in  charge 
at  the  fire,  and  the  first  officer  being  in  charge  of  all  groups  on  deck. 
The  stewards,  purser,  baggage  master,  etc.,  control  the  passengers 
and  muster  them  at  designated  positions.  The  chief  engineer 
and  engineers  on  watch  stay  in  the  engine-room,  the  remainder  of 
the  engineers  beinii;  in  charge  of  their  pumps  and  groups  on  deck. 
The  senior  tele^^rapliist  remains  at  his  instruments,  and  the  doctor 
in  the  surgery  ready  to  attend  injuries. 

Various  members  of  the  crew  are  detailed  to  attend  with 
hoses  and  smoke  hehnets,  and  to  muster  at  the  hydrants  and 
extint^uishers,  and  be  prepared  to  close  bulkhead  doors  and  side 
scuttles  which  are  situated  in  their  particular  section. 

The  details  of  the  procedure  coimected  with  both  fire  and  boat 
drills  are  shown  on  the  same  muster  list,  as  the  latter  is  always 
associated  with  the  former. 

Certahi  oiiicers  are  held  responsible  for  the  necessary  equip- 
ment and  seaworthiness  of  the  boats,  and  their  dutv  is  to  see  that 
tliey  are  at  all  times  ready  for  any  emergency.  The  water- 
breakcMs  in  the  boats  must  be  kept  constantly  fiUed  and  properly 
hishctl  down,  bread  tanks  exaiiuned  frequently , and  the  biscuits  re- 
newed when  necessary.  Careful  exammation  is  made  of  the  davit 
lockings  and  boat  furnishings  ;  the  sliding  chocks  and  swivels  in  the 
lower  blocks  should  be  oiled  and  worked  at  least  once  a  week  at  sea. 


FIRE  AND  BOAT  DRILLS  397 

Before  a  passenger  or  emigrant  vessel  leaves  the  home  port, 
an  inspection  is  made  by  the  Board  of  Trade  Surveyor,  who 
satisfies  himself  that  the  lifeboats  and  their  equipment  are  in 
good  order  and  can  be  manned  by  efficient  crews.  Certain  boats 
are  selected,  and  these  are  swung  out  by  the  davits,  lowered  into 
the  water,  manned  and  exercised  by  their  respective  crews. 

Subject  to  suitable  weather  conditions,  there  is  usually  a 
daily  boat  drill  of  the  deck  hands,  each  watch  being  exercised 
on  alternate  days ;  and  at  definite  periods  the  whole  crew  are 
practised  at  fire  and  boat  drills,  which — ^in  accordance  with  the 
latest  regulations — must  be  at  least  once  a  fortnight. 

The  necessity  for  frequent  drills  cannot  be  sufficiently 
emphasised.  The  success  of  the  operation  of  any  such  scheme  as 
briefly  outlined,  during  a  period  when  a  heavy  sea  is  running  on 
a  dark  night,  when  the  passengers  are  in  a  condition  of  nervous 
excitement,  largely  depends  upon  the  organising  power  of  the 
ship's  officers,  which  can  only  be  made  perfect  by  constantly 
drilling  the  crews,  and  making  the  passengers  accustomed  to 
take  up  their  positions  in  preparation  for  any  emergency. 
The  real  difficulties  can  only  be  appreciated  by  those  who 
have  taken  extended  voyages  to  distant  countries  through 
troublesome  waters. 

Very  searching  inquiries  have  been  made  from  time  to  time 
into  various  shipping  disasters,  and  it  is  to  the  honour  and  glory 
of  the  Mercantile  Marine  Service  that  officers  and  men  have 
"  played  the  game  "  when  faced  with  disaster.  They  have  always 
stood  firmly  at  the  position  of  duty — oftentimes  at  great  personal 
disadvantage — exhibiting  that  spirit  which  has  made  the  name 
of  the  British  seaman  to  be  honoured  and  admired  by  all  peoples 
throughout  the  world.  Safety  for  passengers  has  always  been 
their  first  consideration,  and  it  seems  almost  superfluous  to  print 
in  conspicuous  lettering  on  the  muster  list  that  women  and 
children  must  first  receive  at^ntion. 

To  carry  out  the  instructions  of  the  officers  with  smoothness, 
and  avoid  the  creation  of  excitement  or  panic  among  the 
passengers,  it  is  of  paramount  importance  that  drills  should  be 
constantly,  and  within  definite  periods,  carried  out  on  aU  foreign- 
going  passenger  and  emigrant  vessels.  Passengers  must  be 
organised  and  controlled. 

Irreparable  damage  can  be  done  by  excited  individuals 
interfering  with  the  launching  of  the  boats  and  the  duties  of  the 
crew.  In  many  instances  it  has  been  proved  that  difficulties  with 
the  operating  gear  of  the  boats  and  davits  have  been  traced 


398  SfflPS'  BOATS 

directly  to  unthinking  passengers  manipulating  the  falls  without 
the  assistance  of  the  recognised  boat's  crew. 

However,  there  are  times  when  a  feeling  of  apathy  is  some- 
times exhibited  by  the  crew,  which  can  only  be  explained  from 
the  fact  that  the  men  get  accustomed  to  situations  of  danger, 
and  it  is,  therefore,  most  essential  that  the  oificers  should  maintain 
a  strict  enforcement  of  discipUne  and  a  proper  recognition  of  the 
regulations.  The  writer's  own  experience  on  one  occasion  when 
crossing  the  Atlantic  is  sufficient  evidence  to  make  it  necessary 
to  call  attention  to  the  fact,  that  boat  drills  are  not  always 
carried  out  as  they  are  intended.  The  vessel  left  a  British  port 
for  New  York  in  a  convoy  which  was  attacked  by  submarines 
when  two  days  out  at  sea.  The  passengers  were  never  at  any 
time  during  the  voyage  allotted  to  any  particular  boat,  and  were 
simply  given  instructions  that  at  the  given  signal  they  were  to 
meet  in  the  saloon.  The  crew  were  never  exercised  at  boat  drill, 
but  simply  mustered  on  the  seventh  day  out  from  port,  at  their 
respective  boats ;  it  was  the  opinion  of  the  writer  that  the 
majority  of  the  men,  judging  by  their  attitude,  were  quite 
unacquainted  with  the  necessary  duties. 

Confidence  is  immediately  created  among  the  passengers,  and 
confusion  would  be  avoided  should  disaster  overtake  a  vessel,  if 
the  regulations  in  regard  to  fire  and  boat  drills  were  faithfully 
carried  out  by  the  ship's  officers  and  crew  at  the  recognised 
periods  during  a  voyage.  The  incident  previously  referred  to 
is  only  inserted  to  prove  the  necessity  for  a  closer  supervision  to 
be  exercised  by  the  authorities,  in  maintaining  strict  recognition 
of  the  rules  which  are  issued  to  safeguard  the  interests,  not  only 
of  the  passengers,  but  also  those  of  the  crew. 


PART   IX 

WEIGHTS    OF   LIFEBOATS,    EQUIPMENT,    AND 

MATERIALS 

The  scantlings  of  all  material  used  in  the  construction  of  wooden 
lifeboats  of  Classes  Ia  and  Ib  are  now  practically  standardised 
by  the  British  Board  of  Trade,  and  it  therefore  becomes  an 
easy  matter  to  estimate  the  total  dead  load  which  must  be  sup- 
ported by  the  davits. 

So  much  latitude  has  hitherto  been  given  to  boatbuilders,  owing 
to  the  absence  of  any  detailed  specification,  that  it  became  a  matter 
of  pure  approximation  to  estimate  the  weight  of  boats ;  ship- 
builders were,  therefore,  placed  at  a  disadvantage  when  calcu- 
lating the  sizes  of  davits,  and  the  strength  of  their  associated 
gear. 

TABLE  XXVI. 
Weights  of  Details  of  Boats'  Equipment. 


l>etnil  of  equipment. 


One  gallon  of  oil  in  canister. 
Liquid  binnacle  coni£>a88 
Two  hatchets        .... 
Two-gallon  iron  bucket 

Iron  baler 

Tool  bag  (canvas  sides) 
Brass  lantern        .... 
Six -gallon      water     breaker 

(empty) 

Sea-anchor  with  tripping  line 
( 'opper  dipper  .... 
Matches  in  W.T.  Tin  Box  . 
Oil  bag 


Weight 
In  lbs. 


14 
9 

3i 
4 
2 
2 
3 


I2i 
13 

3  OZ8. 

2  ozs. 
8  OZS. 


*f 


*» 


»» 


9» 


t» 


»» 


Detail  of  eciulpment. 


Ash  oars  13  ft.  long 
14  ft. 
16  ft. 
„      „     16  ft. 
Boat  hook 
Painter 

Sails  and  covers  vary  for  \ 
different  boats.  Those  for  i 
a  boat  24  ft.  in  length  .  ! 
1  gallon  of  water  in  breaker 
Biscuits  per  person  . 
Orutches  (a  set  of  8)  . 
Red  lights  in  cannister    . 


Weisht 
in  lbs. 


15 
16 
17 
18 
5 
24 


30 

10 

2 

5 

5i 


Tlie  writer  lias  weighed  the  various  details  of  equipment  as 
given  in  Table  XXVI.,  and  periodically  checked  the  weights  of  the 


400 


SHIPS*  BOATS 


boat«  with  the  standard  dimensions  shown  in  Table  XXVll.  The 
particulars  have  been  grouped  togetiieo'  in  such  a  form  as  will 
enable  the  shipbuilders  to  readilv  arrive  at  a  veiy  close  estimate  of 
the  total  weight  coming  on  the  davits.  This  informatioii  will 
also  assist  patentees  of  special  appliances  designed  to  operate 
the  launching  of  ships'  boats. 

The  difference  m  weight  between  steel  and  wooden  lifeboats 
con8tract«d  in  Great  Britain  is  now  practically  negligible. 


TABLE   XXVII. 
DP  WOODKK  LlTSBOATS,  CLASsn  Ia  a 


rameriBlnns. 

II 

1 

s 

30-0'x3'C'   X3'75 

607 

2fl-0'x8-76'x3-6' 

546 

28-0'x8-5'   x3-5' 

500 

27  0'x8-26'x3-4' 

454 

i 

1 

43-4 

1 

V 

GO 

1^ 

cwts. 
8S'4 

51 

391 

79-8 

50 

35-7 

73-7 

46 

32-4 

68-3 

40 

29'0 

68-9 

30 

281 

630 

32 

23-2 

47-2 

30 

214 

44-2 

20 

18a 

38-3 

23 

170 

33'9 

■s 

i' 

Cltt*. 

7-0 

s 

ill 

cwM. 
138'S 

■■a 

7-0 

1267 

129-0 

66 

ns-B 

no-o 

6-6 

106-2 

108-1 

6-0 

030 

96-6 

60 

86-1 

87-6 

50 

75-4 

77-6 

5fl 

70-6 

72-7 

4-8 

61-8 

63-5 

4-5 

564 

57-1 

4-0 

49-Q 

61-4 

3-5 

430 

44-3 

39-4 

34-6 
30-0 


The  weights  in  Table  XXVII.  are  based  on  latch  being  uaed 
for  the  planking.  If  teak  is  utihsed  then  the  weight  is  increased 
by  about  three-quarters  of  a  pound  for  every  cubic  foot  of 
capacity  (L  X  B  X  D  X  0-6). 

It  bet^omes  somewhat  difficult  to  state  with  any  degree  of 
accuracy  the  exact  weight  of  the  various  kinds  of  timber  used  in 
the  eniDttniction  of  ships'  boats.     Timber  felled  in  the  spring 


WEIGHTS  OF  LIFEBOATS,  ETC. 


401 


contains  more  moisture  than  that  felled  in  the  winter.  Moisture 
adds  to  the  weight ;  some  trees  when  felled  contain  about 
40  per  cent,  of  moisture,  and  during  the  process  of  seasoning  this 
is  reduced  to  about  15  per  cent.  The  wider  apart  are  the  annual 
rings,  the  more  sapwood  is  present,  and  consequently  contain  a 


greater  amount  of  moisture. 


The  list  of  materials  given  in  Table  XXVIII.  will  be  a  satis- 
factory guide  for  all  practical  purposes  in  boatbuilding.  * 


TABLE   XXVIII. 
Weights  of  Matebials. 


Material. 


Asb,  English 

„    American 
Beech 
Birch 
Cedar 
Chestnut 
Cypress 
Elm,  English 

„  Wych  . 

„  Canadian 
Eir,  Dantzic 

„    spruce   . 
Greenheart 
Hickory 
Inarch 

Lignum  Vita) 
Mahogany,  Cuba 

Honduras 
Lagos 
Gaboon 
Maple 
Oak,  English 

„    live 

„    white   . 

„    African 
l*ino,  red 

„    yellow 

,,    long  leaf 


»» 


«» 


»» 


Weight  la 
lbs.  per 
cub.  ft. 


48 
40 
48 

4:7 

31 

3H 

30 

30 

38 

45 

30 

30 

70 

49 

39 

83 

48 

42 

40 

35 

49 

52 

59 

40 

02 

30 

30 

44 


»» 


Material. 


Pine,  short  leaf 

Oregon 

pitch 
„     white 
Plane  tree   . 
Redwood,  Baltic 

„        California 
Sabicu    . 
Teak      ... 
Alaminium,  cast^ 

„  sheet 

Brass     .     .     . 
Cement,  Portland 
Coal       .     . 
Copper  . 
Cork 
Iron,  cast    . 

„     Mrrought 
Lead 
Leather 
Rubber 
Steel      .      . 
Tar,  bituminous 
Water,  fresh 
.,      river 
M     salt 
Zino       .     . 

Balsa  Wood  (U.S.A.) 


Weight  iu 
ibft.  per 
cub.  ft. 


38 

37 

40 

28 

40 

37 

20 

57 

53 
100 
108 
624 

73 

80 
548 
150 
450 
480 
712 

59 

58 
490 

75 
02-25 

03 

04 
445 
9-12 


Table  XXIX.  shows  the  weights  of  the  occupants  of 
boats  based  on  the  standard  weight  of  one  person  being 
105  lbs. 

2  D 


402 


SHIPS'  BOATS 


TABLE   XXIX 

ViRUiHTi  or   PCBSOSS. 


-No.  of 


2 


if 

7 

H 

•I 
II 

12 

i:{ 

17 
18 

h) 

20 


^'eloht  In  cwta. 

So.  nt 
21 

Wdsht  laevu. 

1  -4732 

30-94 

2'iiO 

22 

32-41 

4-42 

23 

33-88 

57*0 

24 

35-36 

7  37 

25 

36-83 

fi'Hi 

26 

38-30 

1031 

27 

30-78 

1 1  70 

2« 

41-25 

I3  2»i 

20 

42-72 

14  73 

:io 

44-20 

Wi21 

31 

45-67 

I7'*i>i 

32 

47  14 

loir, 

33 

48-62 

20(13 

:u 

50-00 

2210 

35 

51-56 

23'r>7 

30 

53-04 

2.'i-04 

37 

54-51 

2<ir>2 

38 

55-98 

27  Oil 

30 

57-46 

20-40 

40 

5803 

So.  of 


41 
42 
43 
44 

45 
46 
47 

48 
49 
50 
51 
52 
53 
54 
55 
5<) 
57 
58 
59 
60 


lSO-40 
61-87 
63-35 
64-82 
66-29 
,67-77 
60-24 
70-71 
7219 
73-66 
7513 
76-61 
78-08 
79-55 
81-03 
S2*50 
33-97 
85*45 
86-92 
88-39 


PART   X 

SECTION    A.— BOAT    STOWAGE    AND    TRANSPORTING 

ARRANGEMENTS 

One  of  the  most  important  considerations  dealt  with  by  the 
shipbuilder  and  shipowner  in  working  out  the  details  of  design 
for  a  large  passenger  vessel  is  the  question  of  securing  a  practical 
arrangement  on  the  boat  deck,  for  dealing  with  the  satisfactory 
stowage  and  speedy  launching  of  the  ship's  lifeboats. 

The  subject  has  riveted  the  attention  of  the  general  travelling 
public  for  many  years,  mainly  as  the  result  of  several  unfortunate 
and  unavoidable  disasters  which  have  occurred  to  well-known 
ocean-going  passenger  vessels ;  and  to  the  increased  faciUties 
provided  during  recent  years  for  bringing  the  peoples  of  the 
United  States  of  America,  Canada,  Great  Britain,  and  the 
continental  countries,  into  closer  contact  and  with  greater 
frequency. 

Royal  Commissions,  Departmental  Committees,  and  an  Inter- 
national Conference  on  Safety  of  Life  at  Sea — which  included  the 
best  known  authorities  of  all  countries — ^have  considered  in  great 
detail,  all  the  diflSculties  which  surround  the  general  question  of 
equipping  cargo  and  passenger  vessels  with  the  most  practical 
and  satisfactory  appliances,  to  ensure  in  the  future  a  larger 
measure  of  safety  for  both  passengers  and  crews. 

The  regulations  made  by  the  Board  of  Trade  in  regard  to  the 
stowage  of  boats,  rafts,  etc.,  and  embodied  in  the  Rules  for 
Life-saving  Appliances  of  1914,  are  as  follows  : — 

**  (1)  All  boats  and  rafts  shall  be  stowed  in  such  a  way  that, 
''  even  under  unfavourable  conditions  of  list  and  trim,  as  large 
"  a  number  of  persons  as  possible  may  be  embarked  in  them,  and 
"  that  as  large  a  number  of  the  boats  as  possible  shall  be  capable 
''  of  being  launched  on  either  side  of  the  ship.  The  additional 
"  boats,  or  rafts,  may  be  stowed  in  rows  across  a  deck,  bridge, 
"  or  poop,  or  approved  appUances  for  transferring  the  boats,  or 
"  rafts,  from  one  side  of  the  deck  to  the  other  may  be  employed. 


"  CI 

fl 

ii 
a 
a 


404  SHIPS'  BOATS 

"  (2)  One  or,  if  necessary,  two  of  the  additional  lifeboats  may 
"  be  stowed  under  the  Ufeboats  of  Class  I.  attached  to  the  davits. 

"'  (3)  Additional  Ufeboats  may  be  stowed  in  tiers  of  two  or 
"  three  one  above  another,  or  they  may  be  fitted  one  within 
"  another,  on  condition  that  means  are  provided,  to  the  satis- 
"  faction  of  the  Board  of  Trade,  for  readily  attaching  them  to  the 
**  davits,  and  lowering  them  into  the  water. 

'"(4)  Where  a  boat  is  stowed  underneath  another  boat  there 
"  shall  be  provided  approved  removable  supports  or  other 
*'  approved  appUances,  so  as  to  secure  that  the  weight  of  a  boat 
"  is  not  unduly  supported  by  the  boat  underneath  it. 

(5)  Boats  may  only  be  stowed  on  more  than  one  deck  on 
condition  that  proper  measures  are  taken  to  prevent  the  boats 

*'  from  a  lower  deck  being  fouled  by  those  from  a  deck  above. 

(6)  All  other  buoyant  apparatus,  lifebuoys  and  life-jackets 
shall  be  so  stowed  as  to  be  readily  available  in  case  of 
emergency/' 

it  has  been  clearly  demonstrated  in  all  disasters  at  sea  how 
difficult  it  is,  even  in  calm  weather,  to  make  full  use  of  all  the 
boats  that  are  stowed  on  board. 

The  necessity  to  provide  "  boats  for  all "  is  a  problem  of 
increasing  importance,  in  view  of  the  large  number*  of  persons 
which  are  being  carried  on  the  modem  passenger  vessel. 

The  *'  raft "  and  *'  buoyant  apparatus  "  were  very  distinct 
and  noticeable  features  of  the  equipment  of  all  vessels  sailing 
through  the  danger  zone,  during  the  recent  piratical  and  devilish 
submarine  war  on  merchant  ships.  It  was  impossible  to  provide 
actual  seating  accommodation  in  the  available  boats  on  a  large 
number  of  the  vessels  transporting  troops  overseas,  consequently 
great  quantities  of  rafts,  Hoats,  etc.,  were  carried  in  addition  to 
the  usual  life-saving  equipment. 

The  destruction  of  the  ship's  boats  caused  by  torpedoes  and 
mines  was  so  extensive  that  the  necessity  for  large  numbers  of 
rafts  is  (j^uite  apparent. 

In  view  of  recent  experience  it  seems  almost  essential  to 
perinaneutly  ecjuip  all  ocean-going  vessels  with  a  certain  per- 
centa«.^e  of  rafts  or  buoyant  apparatus,  without  weakening  the 
present  rules  for  boat  stowage. 

Rafts  whicli  are  of  a  convenient  size  for  man-handling,  are 
sufficient  for  an  emergency,  and  which  wall  succour  a  nimnber  of 
persons  for  even  a  few  hours  only,  have  often  provided  the  means 
of  sustaining  life  until  reUef  arrives  from  the  ship's  boats  or  from 
anotlier  vessel  in  the  immediate  neighbourhood  of  the  disaster. 


BOAT  STOWAGE, 

To  provide  satisfactory  means  for  stowing  and  handling  the 
lar;j;e  number  of  b()ata  required  by  the  Kules  for  Life-savinj; 
Appliances,  it  has  been  necessary  to  stow  in  tiers  a  laFj^e 
portion  of  the  boats  having  collapsible  bulwarks  (Class  II.). 
far,  it  lias  been  found  practically  impossible  Ui  atow  all  the  life- 
boats within  the  sweep  of  the  actual  laimchiog  and  lowerinfj 
apparatus.  It  is  therefore  necessary  to  provide  some  mechamcal 
means  of  transporting  the  boats  from  the  stowing  to  the  laimching 
positions  under  the  davits,  or  other  lowering  appliance. 

In  case  of  disaster,  the  vessel  would,  in  all  probability,  take  a 
list,  and  it  is  therefore  essential  to  make  compiilaory— where 
boats  are  stowed  inboard  or  across  the  deck — the  fittinj;  of  some 
mechanical  means  in  the  form  of  transporting  gear,  that  will  be 
strong  cnoiifjh  and  siifiicipntly  effective,  in  bringing  the  boats  from 
their  stowing  positions  to  the  davits. 

It  largely  depends  on  the  type  of  davit  proposed  to  be  fitter!, 
as  to  the  most  suitable  arrangement  of  transporting  ap|iaratuK. 

A  feature  in  connection  with  the  st^twajje  of  ships'  boats 
which  is  often  lost  sight  of  by  the  shipowner,  is  the  provision  of 
suitable  means  of  access  to  the  interior  of  the  boat  for  periodical 
ins|)ection. 

With  the  present  arrangement  of  stowing  pontoon  lifeboats 
in  a  crowdej  condition  on  the  boat  deck,  and  covered  up  with 
canvas,  it  is  quito  possible  to  imagine  that  the  l>tiats  are  never 
inspected  internally,  except  at  the  annual  survey. 

The  life  nf  a  boat  not  only  depends  on  the  quality  of  the 
conetructioii — to  which  sufficient  attention  has  already  been 
given — but  also  upon  the  means  which  are  adopted  Ui  maintain 
a  aystoniatic  inspection  of  the  condition  of  the  interior  and  extonor 
of  tJie  hull.  The  stowage  should,  therefore,  be  so  arranged  as  to 
permit  of  easy  access  to  each  boat. 

The  matter  presents  some  difficulty,  owing  to  the  required 
number  of  boats  ami  the  limited  available  space  for  stowage. 
A  glance  at  the  photograph  in  the  frontispiece  will  give  the  reader 
some  idea  of  the  crowded  condition  of  a  boat  deck. 

The  Martin  Patont  Boat  Transporter  has  been  fitted  tio  a 
large  number  of  well-known  passenger  vessels,  including  the 
Ai/uUtinm,  Adriatic.  Baltic,  etc. 

Illustrations  of  the  apparatus  are  given  in  Figs.  224.  22f) 
and  -iafi. 

The  transporter  conaist.s  of  two  carriers  fitted  with  choclre 
to  carry  one  or  more  lifeboats,  tlie  carriers  being  enpportetl  on 
rollers  which  run  on  two  trackways  leading  to  the  vessel's  side. 


406  SHIPS"  BOATS 

One  roller  of  foch  cftirier  Is  titled  with  pina  which  meaft  iin 


225.^Tho  "  Mnrtin  ",  put^'nt  boat  transporter.    Tractwaj-a  stowed. 

correaponding  holes  in  the  tracks,  these  pinned  rollers  being 
connected  together  with  a  shaft. 


BOAT  [STOWAGE,  ETC. ' 


407 


By  turning  a  crank  which  actuates  a  wurm  gear,  the  shaft  is 
revdivecl  and  the  transporter  is  moved  atliwartehip,  bringing  the 
boat  from  the  inboard  position  to  the  davit  for  launching  over- 
board. 

Throughout  the  process  ot  moving  the  boat,  the  apparatus 
is  under  full  control  bv  the  worm  fi^arinf!,  and  the  boat  cannot 
take  chart;e. 

As  will  be  seen  [from  Figs.  224  and  225  the  traekwaya  can  he 
hinged  and  stowed,  leaving  a  clear  passage  on  the  deck  each  side 
of  the  boat. 

A  very  neat  and  effective  transporter  has  also  been  designed 
by  Mr.  G.  Tumhull.  M.Inst.N.A..  of  Messrs.  Alfred  Holt  and  Co., 
Ltd.  Tlie  arrangement  does  not  call  fur  any  4'f*i*'  description, 
for  the  various  designs  of  transporters  are  very  mueh  ahke  in 
principle,  but  differing  in  details.  A  feature  in  connection  with 
this  apparatus,  which  must  appeal  to  every  ship's  officer,  is  the 
satisfactyr)' pnitcction  which  is  given  to  the  trackway,  from  the 
entrance  of  grit  and  dirt,  enabling  the  transporter  t*)  be  always 
in  a  condition  for  meeting  an  emergency. 

As  will  be  seen  from  Fig.  227,  the  inboard  boat  was  trans- 
ported and  the  mechanism  operated  by  one  man.  The  photo- 
graph shows  the  outer  boat  ready  for  lowering  and  the  inner 
boat  transported  to  the' outer  position  ready  *<»  be  hooked  on  to 
the  falls. 

It  will  be  of  general  interest  to  state  that  in  a  vessel  fitted  with 
Tumbull's  Patent  Davit  Turning  Out  Gear  and  Patent  Trans- 
porter, during  the  official  tests  in  Glasgow,  the  whole  operation 
of  lannching  two  Class  I.  bciats,  sf-iwed  abreast  of  one  another, 
only  occupied  twelve  minutes.  This  same  vessel  was  torpedoed 
in  the  Atlantic,  and  all  the  passengers  and  crew  were  safely 
landed  with  thn  boats. 

The  Welin  system  of  traversing  boats  from  one  side  to  another 
acoks  t)J  provide  a  way  out  ot  the  difficulty  of  inboard  stowage. 

The  outboard  boats  are  provided  with  folding  chocks,  the 
inboard  boats  having  fixed  chocks  of  a  simple  construction,  which 

also  hinged.  A  trolley  running  on  rails,  operated  by  means 
of  an  endless  wire,  allows  a  free  travel  from  one  side  of  the  ship 
to  the  other,  and  being  self-locldnj?,  obviates  any  danger  of  the 
boat  taking  charge.  The.  trolley  itself  is  provided  with  two 
temporary  lifting  chocks,  the  arms  of  which  are  extended  in  such 
a  way  as  to  form  levers,  and  by  simply  heaving  on  a  small  set  of 
purchase  blocks,  these  levers  are  brought  together,  lifting  the  boat 
(and  holding  it  temporarily  steady)  sufficiently  to  clear  the  keel 


SHIPS'  BOATS 


r 

I 


BOAT   STOWAGE,  ETC. 

over  the  other  cliocks  in  their  hinj^ed  down  position.  Tlie  boat 
may,  therefore,  be  moved  without  hindrance  from  one  side  of 
the  eliip  to  the  other.  The  traversing  standard  ia  deaigne<l  to 
give  greater  power  or  gitiater  speed  according  to  circiiniatances. 

The  same  system  may  satisfactorily  be  modified  to  deal  witli 
two  boats,  and  a  single-acting  davit  thereby  installed  instead  of  a 
double-acting,  if  desirable. 

The  various  systems  have  much  to  commend  them  to  the 
favourable  consideration  of  the  shipowner,  but  the  problem  of 
boat  transportation,  when  the  vessel  is  heavily  liste-d,  is  one  of 
considerftble  difficidty.  more  than  thr  iion-seiifaring  r 
patra,    and    the   success    of    any    inst-allalion   depend? 


Mi'lh'Hl  of  iiltir^:  doiihlo  m 


:  I'hookrt.      (InlHiiird  nnd  niillHinril.) 


simplicity,  speed,  and  a  trained  erew  for  manipulation.  It 
remains  t«  be  seen  in  the  future  days  of  ship  construction,  whether 
the  stowage  arrangements  can  be  impnived,  for  there  is  abundant 

I  scope  for  the  exercise  of  ahitity  and  ingenuity. 
The  position  of  the  supporting  chocks  ia  at  the  quarter  lengths 
of  boat  from  sti'ni  and  st«nipost,  This  standard  practice  enables 
the  b(}atbnilder  to  fit  pad  pieces  on  the  wooden  boats,  or  doublbig 
plates  on  the  steel  boat«,  in  way  of  the  chocks.  The  pad  jjii-ces 
protect  the  boat  and  simplify  the  construction  of  tlie  chock. 
It  is  a  matter  of  opinion  as  t«  the  desirability  of  having  double 
or  single  chocks  fitted  at  each  end  of  the  boat.  It-largely  depends 
on  the  type  of  davit  fittwl.  There  is  no  doubt  that  the  double 
chock  {Fig.  228)  gives  bettor  support  to  tlie  boat,  especially  in 


I 


f! 


I 

f  ; 

I 

. 


410 


SHIPS'  BOATS 


view  of  the  fact  that  the  boats  are  well  griped  down  to  i 
deck  on  the  unsupported  side,  where  the  single  chock  (Fig.  2i 
at  each  end  is  fitted.  On  the  other  hand,  every  facility  shoi 
be  ^iven  to  allow  the  boats  to  swing  out  quickly  at  an  emergenc 
and  it  is  possible  where  the  outward  chock  is  dispensed  wil 
for  the  boat  to  be  pushed  outboard  without  being  actually  lift 
by  the  falls.  It  is  considered  preferable,  in  any  case,  whetfa 
inboard,  or  outboard  and  inboard  chocks  are  fitted,  that  th 
should  each  be  made  to  slide  and  hinge  down,  with  the  upp 
portion  low  enough  to  be  below  the  top  of  the  fixed  deck  choc 
to  prevent  dama<2;e  from  the  keel  of  the  boat,  as  shown 
elevation  in  Figs.  22!)  and  281. 

It  is  necessary  wlien  fitting  the  inboanl  and  outboard  choc 


Fig.  230. 


Fio.  2: 


Mcthcxl  of  iittini;  sin^rh;  stowingjchocks.     Jnboard.J 


to  arrani^'o  for  tlio  fixed  l)as(»  to  have  a  st^^p  immediately  in  wi 
of  the  keol,  as  sliowu  iu  Fiir.  22S,  to  permit  of  the  boat  beir 
cjuickly  swiin^  out  in  tlie  davits  without  the  necessity  of  usii 
the  falls  to  lift  the  boat. 

A  slidiuir  chock  is  sometimes  fitted  as  shown  in  Fiir.  281  a.  tl 
s]i<lm«^'  porticm  l)ein<,'  dovetailed  into  the  fixed  chock.  Ti 
sclieme.  however,  is  not  recommended,  as  the  weather  tends  t 
swell  th(^  material  and  prevent  easy  manipulation. 

Messrs.  Welin  Davit  and  P^ngineering  (Jo.  have  several  pater 
st^)wage  chocks.  Two  types  are  illustrated,  the  one  in  Fig.  28 
consists  of  an  inner  and  an  outer  chock.  The  outer  chocks  ar 
hinged  clear  of  the  boat  before  launching  by  the  aid  of  a  releasin 
rod  and  a  geared  wlieel.     By  unscrewing  the  wheel  and  liftin 


BOAT  STOWAGE,  ETC. 


411 


it  clear  of  the  bracket  attached  to  the  inboard  chock,  the  outer 
chock  is  pushed  clear  of  the  boat's  keel.  Patent  gripes  are  so 
fitted  that  when  the  inboard  slips  are  relieved  the  outboard  gripes 
become  disconnected  at  the  same  time. 

It  is  necessary  that  all  gripes  should  be  fitted  with  slips  and 
hemp  lashing,  so  that  if  difficulty  is  found  with  the  slips  the 
lashing  can  be  cut  asunder  and  the  boat  released. 

The  second  type  of  patent  stowing  chock  is  shown  in  detail 
in  Fig.  288.  The  purpose  of  this  design  is  to  permit  of  the  boats 
being  stowed  in  a  position  to  allow  them  to  be  partly  outboard, 
ready  for  an  emergency.  An  extreme  inboard  position  is 
provided  by  the  upi)er  porticm   of  the   chm^k   sliding   inboard. 


/'^  rf/vr  c^/^£ 


SECTIONAL  VIEW  ELEVATION 

Fro.  232. — The  "  Welin  "  patent  stowing  chocks  and  gripPs. 

being  secured  to  a  deck  plate  by  a  clamp  screw.     The  various 
details  shown  in  the  sketch  are  as  follows  :  — 

A.  Bracket  attached  to  sUding  chock  to  which  the  tumbler 
or  keel  rest  is  hinged. 

B.  Tlie  clamping  deck  plates  for  securing  sliding  chock  in 
position. 

C.  The  clamping  screw  or  eye-bolt  for  securing  sliding  chock 
to  deck  plates. 

D.  The  clamping  tail  piece  attached  to  sHding  chock. 

E.  Tension  rod  connected  to  tumbler  for  relieving  the  keel 
of  boat. 

F  and  G.  Staple  and  pin  to  secure  tension  rod  in  position. 
H.  Stopper  plate  limiting  the  sliding  chock  in  its  outboard 
position. 


SHIPS'  BOATS 


■   PLAN,    WITH  X^NPTENaON-HOOWEMOVED   - 


'LAN.   wn-H  Si-ioiHG  C  HOC  K  REM  I 


a. 


d.. 


I''ni   i(3,— Tlio  ■■  Wfl 


It  iiinj^le  etou'ing  chocka. 


BOAT  STOWAGE,  ETC. 


41S 


K.  Guide  baiu. 

L.  Handgrips. 

M.  Eye  for  taking  boat's  gripes, 

N.  Securing  bolt  for  tumbler, 

0.  Timibler  or  keel  rest. 

P.  Securing  bolta  for  bracket  A. 

U.  Countersunk  bolts  for  tailpiece. 

X  and  Y.  Sliding  chock. 

Z.  Fixed  base. 

The  position  of  the  stowage  diocks  in  I'elation  to  the  davits 
should  be  such  that  the  heads  of  the  latter  plumb  the  Ufting  hooks 
in  the  boat.  It  is  not  an  uncomtnon  occurrence,  in  order  to  keep 
a  wide  passage  between  the  lifeboats  and  raachinerj-  casings, 
to  find  tiie  lifeboats  stowed  outboard  of  a  vertical  line  from  the 
davit  head,  with  the  consequence  that  when  the  boats  are  .lifted 
after  great  difficulty,  they  swing  inboard  and  are  likely  to  injure 
persons  in  the  vicinity.  Satbfactory  boat  stowage  should  be 
arranged  in  the  first  place  and  the  passage  ways  made  to  suit. 

There  is  a  tendency  with  the  shipbuilder  of  the  ordinary 
cargo  vessel  to  limit  the  overhang  of  the  ordinary  radial  davits 
in  order  to  save  material,  which  results  in  the  rubbers  of  the  boat 
coming  into  contact,  with  the  davit.  Care  must  be  exercised 
in  planning  the  position  of  the  davit  head  and  heel  in  relation  to 
the  lifting  hook,  so  that  the  weight  of  the  boat,  when  the  vessel 
is  upright,  practically  enables  it  to  swing  out  easily  into  the 
outboard  position.  The  falls  from  the  davit  head  to  the  lifting 
hook  should  be  in  a  vertical  hue  throughout  the  operation, 
otherwise  it  needs  extra  power  to  push  the  boat  out,  which  means 
that  you  practically  have  U>  lift  the  boat  in  the  falb  to  permit  of 
clearing  the  davit«.  A  little  prehminary  care  exercised  in  the 
drawing  office  with  a  paper  plan  model  of  the  boat,  will  save  a 
great  deal  of  inconvenience  and  money  to  the  shipbuilder. 

Wlien  the  vessel  is  upright  there  should  be  twelve  inches 
clearance  between  the  boat  and  the  ship's  side  at  the  light  water- 
line  when  the  boat  is  lowered  overboard. 

The  ordinary  cargo  vessel  of  say  5500  try  WXH)  tons  gmsa 
tf>nnage,  carrying  a  crew  of  about  sixty,  usually  has  a  boat  deck 
extending  out  from  the  machinery  casing  to  the  ship's  side,  and 
situated  thereon  are  one  or  two  open  lifeboate  of  Class  1.  on  each 
side.  On  the  navigating  bridge  the  two  small  Class  III.  boats  are 
stowed  under  davits.  When  designing  the  boat  arrangement. 
the  platforms  or  boat  deck  should  always  be  of  sufficient  length  to 
permit  members  of  the  crew  passing  round  the  boat  to  make  any 


414  SHIPS'  BOATS 

adjustment  to  the  davits,  falls,  or  gripes,  and  thus  obviate  the 
necessity  of  climbing  over  the  boats. 

One  of  the  most  important  factors  which  governs  the  successful 
operation  of  launching  a  boat,  is  the  efficiency  of  the  lifting  and 
lowering  gear.  The  practice  of  simply  taking  ajtum  round  the 
davit  with  the  fall  when  the  boat  is  being  lowerea  into  ihe  water, 
in  order  to  check  the  speed,  is  often  responsible  for  accident. 
There  should  be  a  combined  bollard  and  sheave  at  the  heel  of  the 
davit  as  shown  in  Fig.  241,  or  a  snatch  block  fitted  as  shown  in 
Fig.  239.  In  each  case  the  falls  can  be  taken  across  the  deck, 
which  allows  a  number  of  men  to  speedily  lift  and  easily  control 
the  boat  and  davits. 

Additional  blocks  or  fairleads  can  be  fitted  to  the  deck,  which 
will  enable  a  lead  to  be  taken  to  the  winches,  and  faciUties  thus 
provided  for  hauling  up  the  boats  on  deck  with  the  least  amount 
of  effort.  ^ 

The  question  of  getting  the  boats  back  speedily  on  board  to 
their  stowing  positions  is  not  of  paramount  importance,  but  it  is 
an  item  which  the  chief  officer  is  more  than  interested  in,  when 
boat  drills  are  of  such  frequent  occurrence. 

The  relative  value  of  the  single  wire  purchase  system  compared 
with  the  multiple  purchase  is  a  much  debated  question. 

With  a  single  wire  rope  the  power  required  for  manipulation 
is  much  greater.  The  clutches,  brake  gear,  and  the  whole  con- 
struction of  the  mechanism  associated  with  the  control  gear  miist 
be  of  heavy  scantling,  compared  with  the  gear  that  is  associated 
with  a  double  or  treble  purchase  system. 

Care  should  always  be  exercised  when  using  new  manilla 
falls,  to  stretch  thcin  well  before  they  are  rove  through  the  blocks, 
afterwards  taking  the  turns  out  and  making  the  necessary 
adjustment  at  the  beckct  to  ensure  smooth  working. 

The  sizes  of  falls  and  blocks  have  been  left  to  tiie  opinion  of 
the  individual  shipbuilder,  in  the  absence  of  any  particulars 
issued  to  guide  him  in  this  important  i)ro vision.  The  \^Titer 
has  a  personal  antipathy  to  wooden  blocks.  This  opinion 
may  not  be  shared  by  others,  but  these  fittings  are  often 
of  very  doubtful  design  and  inferior  (juaUty,  are  very  rarely 
tested,  and  quickly  deteriorate.  The  cheeks  have  often  been 
scored  and  even  forced  apart  dining  the  operation  of  lowering 
the  loaded  boat  for  the  first  time,  because  the  size  and  tj-pe  were 
unsuitable  for  the  purpose.  You  nuist  have  weight  in  the  blocks 
to  assist  the  falls,  and  this  i)articularly  applies  to  the  non-toppling 
designs.     The  most  successfid  and  useful  design  of   blocks   is 


BOAT  STOWAGE,  ETC. 


415 


conBidered  by  many  men  witli  sea-going  experience  to  be  of 
m&lleable  cast  or  wiuugbt  iron. 

Where  more  than  one  boat  is  served  by  one  set  of  davits  it  is 
moat  essential  that  special  provision  should  be  made  to  prevent 
the  lower  blocks  from  "  toppling,"  and  the  cables  from  becoming 
twisted,  or  what  is  termed  "  cable-laid."  These  difficulties 
cannot  be  avoided  with  the  ordinary  wood  block  when  the  falls 
are  recovered  quickly.  To  obviate  the  drawbacks  associated  with 
the  ordinary  block  many  devices  have  been  patented  and  placed 
on  the  market. 

The  Bulman  Patent  Boat  Block  .Syndicate  of  Great  Eastern 


patent  bout  block. 


Street,  London,  have  designed  a  special  apparatus  termed  the 
"  Bulman  "  Patent  Lifeboat  Lowering  Gear,  which  consists  of 
blocks  made  with  the  shell  or  frame  extended  vertically  upwards 
and  formed  with  a  slot  or  opening  extending  right  across  the  block 
above  the  sheaves.  This  opening  is  adapted  to  receive  an  end 
of  a  bar  or  rod,  preferably  rectangular  in  shape,  and  which 
extends  across  between  the  two  lower  blocks  attached  to  the 
falls,  and  is  thus  adapted  to  prevent  the  blocks  turning  over 
(toppling),  or  the  falls  from  twisting  (cable-laid). 

In  order  that  the  spar  or  stroi^back  can  be  easily  detached, 
if  found  necessary,  a  patent  tumbler  arrangement  on  top  of  the 
block  is  fitted,  which  holds  the  spar  securely  in  position,  and  at 


41C 


tlK- 


SHIPS'  BOATS 
can   bu    speedily    detached     by    liftjng     the 


tumbler. 

-Vii  ilhistnitiuii  (.f  the  apparatus  id  jriven  in  Pig.  234. 

Several  non-t">i>jiliiii.'  blocks  are  now  available  for  purchase, 
but  vpn-  few  justify  their  description,  for  practically  all  of  Uiem 
arc  dependent  ujnm  ;;uide  plates  in  some  form  or  another,  which 
do  not  in  uiiv  way  iiiilitfy  iir  remove  the  inherent  tendency  of  the 
block  to  topple,  but  mily  prevent  it  from  so  toppling  by  guiding 
the  falls  at  the  expense  of  a  certain  amount  of  chafiiig.  An 
illustration  of  the  Weliii  Patent  Non-Toppling  Block  is  given  in 


diifij'i 
niilv 

bl.H'k 


hd  .Ml- 
.'111  ]>[< 


.   purl.  1 


-  k..,>1  i, 
:  tmi.-iL  h 


M  hr  ]ii;«lr  to   I 
l.vk  ilJld   loi.kill- 


fiv.viii- fills  in  blocks. 

:!:)-1.  Tlic  principle  ia  veiy  simple,  the 
tliut  the  ceiit;ro  sheave  of  tlie  bottom 
nks  uri'  love  in  such  a  way  that  the 
■i  lir.st  over  tlie  raised  sheave,  so  that 
■Mvs  triiiisiiiittcd  |.hniuj;h  this  sheave,  the 
I  (in  ii|iH-lit  condition, 
i;  i;xcriisiil  by  the  shipbuilder  when  reeving 
iiistiii'-iiiins  arc  issued  by  the  Wehn  Davit 
■V  till'  iiiiidaiice  of  sliipbuilders.  Reference 
-.  'S-Wi.  and  from  the  position  of  standin>r 
iiilbniird  ut  the  side  of  the  block  opposite 


BOAT   STOWAGE,  ETC.  417 

to  the  becket,  the  fall  must  always  be  rove  from  the  inboard  tread 
of  the  bottom  sheave  over  the  outboard  tread  of  the  top  sheave. 
This  will  prevent  twisting  and  chafing.  Although  contrary  to 
accepted  practice,  these  instructions  are  the  outcome  of  experi- 
ments made  by  the  firm,  and  the  falls,  with  their  particular 
blocks,  must  be  rove  as  shown ;  imless  the  quickest  running  part 
passes  round  the  raised  centre  sheave  of  the  bottom  block,  the 
efficiency  of  the  whole  gear  will  be  entirely  destroyed. 

/^jiother  method  of  reeving  manila  falls  through  a  treble 
purchase  block  is  shown  in  Fig.  236. 

It  is  of  interest  in  connection  with  this  portion  of  the  subject, 
to  read  from  their  report  the  recommendations  of  the  Depart- 
mental Committee  on  Boats  and  Davits  in  1913,  in  the  case  where 
more  than  two  boats  are  served  by  one  set  of  davits  : — 

"  (a)  A  gear  must  be  fitted  of  sufficient  power  to  turn  the  boat 
"  out  against  a  considerable  list. 

"  (6)  There  must  be  positive  control  in  all  positions. 

"  (c)  Wire  falls  should  be  used,  and  we  recommend  either  a 
**  single  or  gun  tackle  purchase. 

'*  {d)  The  falls  should  be  led  to  drums  fitted  with  a  powerful 
"  and  reliable  hand  brake  for  controlling  the  lowering  of  the 
"  boat. 

''  {e)  The  winding  gear  must  be  so  designed  that  it  is  possible 
"  to  adjust  the  trim  of  the  boat,  in  order  that  if  the  vessel  is  down 
"  by  the  head  or  the  stem,  the  boat  may  be  lowered  into  the 
**  water  on  an  even  keel.  This  should  apply  to  all  cases  in 
"  which  the  winding  gear  is  used. 

"  (/)  For  hoisting  the  boat  and  recovering  the  falls  rapidly, 
**  there  should  be  a  quick-return  geared  hand- winch  to  which 
*'  some  system  of  power  might,  with  advantage,  be  fitted  as  an 
"  auxiUary. 

"  {(j)  If  the  tackles 'consist  of  more  than  a  single  part,  some 
**  approved  type  of  non-toppling  blocks  should  be  fitted  to  prevent 
''  the  falls  from  fouling  when  they  are  recovered.  When  the 
''  tackles  consist  of  several  parts,  there  is  a  serious  risk  that  the 
''  lower  blocks  will  capsize.  Several  types  of  blocks  have  been 
"  designed  which  overcome  this  difficulty  with  varying  success. 
**  The  simplest  arrangement  which  we  have  seen  is  that  of 
"  weighting  the  lower  blocks  below  the  sheaves  and  carrying  the 
"  cheeks  of  the  lower  blocks  above  the  top  of  the  sheaves  to 
**  prevent  toppling,  and  fitting  a  span  between  the  blocks  with  a 
"  weight  in  the  centre  to  prevent  the  falls  cable-laying.  We 
*'  think  that  this  arrangement  should  prove  quite  satisfactory 

2  E 


418  SHIPS'  BOATS 

'*  with  a  gun-tackle  purchase.  It  is  probable  that  other  types  of 
**  blocks  exist,  or  will  be  devised,  which  will  overcome  this 
"  difficulty.  We  refrain,  therefore,  from  reconmiending  any 
"  particular  type,  but  suggest  that  in  cases  where  more  than  two 
'*  boats  are  served  by  one  set  of  davits,  the  Board  of  Trade  ahould 
''  satisfy  themselves  that  reliable  non-toppling  blocks  are  fitted." 

Special  precautions  shoidd  alwa3rs  be  taken  to  stow  the  falls 
in  such  a  way  that  they  are  ready  for  use,  immediately  the 
necessity  arises.  To  simply  dump  them  down  into  the  boat  or 
let  them  lie  about  the  deck  is  to  court  disasteir. 

A  number  of  passenger  vessels  are  fitted  with  special  barrels 
or  tubs,  into  which  the  falls  are  coiled,  but  the  general  opinion  is 
that  the  most  serviceable  and  effective  fitting  b  the  reel. 

The  majority  of  up-to-date  passenger  or  emigrant  veesels 
are  fitted  with  emergency  lighting  apparatus,  to  enable  the  boat 
and  promenade  decks  to  be  well  lighted  in  case  of  accident  to 
the  ship's  dynamos.  Over  each  lowering  station  should  be  fitted 
a  cluster  of  lights  to  facilitate  the  operation  of  launching  the 
boats  and  embarking  the  passengers.  The  lighting  system  may 
be  rendered  inoperative  by  accident ;  suitable  hand  lanterns 
.  should  be  stowed  in  convenient  positions  as  a  means  of  guiding 
passengers  to  the  boat  stations. 

Complaint  is  sometimes  received  from  ships'  officers  of  the 
unreliability  of  tarred  manila  for  use  as  davit  falls ;  instances 
have  occurred  when  the  boat  has  dropped  at  one  end  without 
the  slightest  warning  being  given  by  the  appearance  of  the 
manila  rope.  The  cause  for  the  defect  may  have  been  in  the 
method  of  treating  the  rope,  but  there  is,  nevertheless,  a  very  big 
variation  in  the  quality  and  price  of  manila  rope  falls,  and  it  is  a 
question  for  consideration  whether  it  would  not  be  advisable  to 
enforce  a  limiting  standard.  Further  reference  is  made  to  this 
subject  in  Part  X.,  Section  B.  * 

During  the  rt^cent  Jiubniarine  menace  each  boat  was  suppUed 
with  two  painters,  one  being  fitted  with  a  strop  and  toggle,  and 
the  end  led  forward  and  kept  belayed  to  a  cleat  or  other  suitable 
fitting  fixed  on  the  deck  or  bulwark.  The  purpose  of  this  pro- 
vision was  to  enable  the  boat  to  be  lowered  into  the  water  when 
the  vessel  was  on  the  move,  and  permit  the  boatmen  disengaging 
the  lower  blocks  attached  to  the  falls  from  the  hooks  in  the 
lifeboat. 

This  pro\ision  is  of  special  importance  where  the  boats  are 
stowed  on  the  poop,  the  painters  secured  to  the  vessel  prevent 
them  coming  into  contact  with  the  propellers. 


BOAT  STOWAGE,   ETC.  419 

It  is  sometimes  necessary  to  stow  the  lifeboats  at  such  a 
height  as  will  enable  them  to  swing  clear  of  a  fixed  bulwark,  in 
which  case  a  simple  chock  and  standard  made  up  from  plates  and 
angles,  as  illustrated  in  Fig.  242,  is  a  useful  and  serviceable 
fitting.  The  photograph  incidentally  shows  TumbuU's  Patent 
Davit  Tuming-out  Gear  fitted  to  a  socket-davit. 

The  same  measure  of  safety  should  be  given  to  the  crews  of 
cargo  vessels  as  in  passenger  ships.  Insuiiicient  care  and  atten- 
tion are  often  displayed  in  treating  all  the  considerations  con- 
nected with  the  life-saving  appUances  of  an  ordinary  cargo  vessel. 
The  davits  and  boats  are  installed  at  a  very  late  period  during 
the  construction  of  the  ship,  the  davits  rigged  and  the  details  of 
equipment  supplied  at  the  last  moment — often  when  the  vessel 
is  loading  her  cargo — giving  inadequate  opportunity  for  the 
surveyor  to  have  all  the  boats  swung  out  in  the  davits  and  lowered 
into  the  water. 

The  question  of  suitably  providing  stowage  for  the  lifeboat  of 
some  of  the  small  Home  Trade  vessels  which  cannot  be  equipped 
with  davits,  is  often  overlooked  and  inadequately  dealt  with. 
Vessels  which  proceed  outside  the  smooth  water  Umits  occasion- 
ally run  into  heavy  weather,  e.g,  the  passage  between  the  Clyde 
ports  and  Belfast  is  very  difficult  at  times  for  a  large  vessel  to 
safely  negotiate.  Effective  arrangements  should,  therefore,  be 
made  for  the  launching  of  the  hfeboat. 

A  typical  arrangement  is  shown  in  Fig.  237,  where  portable 
stowing  chocks  are  fitted  to  a  cross-piece  and  attached  to 
stanchions.  The  cross-piece  takes  the  weight  of  the  boat  off  the 
hatches.  The  derrick  is  stowed  at  a  height  that  will  enable 
the  boat  to  be  launched  without  the  necessity  to  top  the  former. 
Suitable  guy  ropes  and  cleats  are  fitted  to  control  the  operation 
of  launching.  A  wire  bridle  with  shackles  and  hook  are  kept 
in  the  boat  and  attached  to  the  lifting-gear  on  the  derrick. 

A  modification  of  this  arrangement  can  be  made  to  suit  the 
requirements  of  most  of  these  small  vessels,  and  where  a  derrick 
is  not  available,  the  lifting-gear  can  be  operated  by  the  provision 
of  a  berthon  and  tackle  from  the  rigging.  The  main  consideration 
is  to  be  able  to  laimch  the  boat  on  either  side  of  the  vessel  without 
much  effort  to  lift  it  from  the  stowage  chocks  and  over  the 
bulwark.  To  simply  stow  the  boat  on  tiie  hatches,  lash  it  down 
to  ring  bolts,  and  rely  on  man-power  to  push  it  overboard,  is 
considered  inadequate  and  dangerous. 

An  important  portion  of  the  life-saving  equipment  of  all 
ocean-going  passenger  vessels,  is  the  provision  of  suitable  rope 


420 


SHIPS'  BOATS 


ladders,  stowed  in  convenient  positions  around  the  boat  stat 
securely  fixed  to  the  bulwark  or  ship's  side  and  coiled  up  in  si 


OMfUff  - 


W 


'T 


DETAILS  OF  - 

CHOCKS  etc. 

* 

•      A   >. 

.    .                       •                                 _           .        -    . 

r'-EVATION    - 

! 


:  I 


^^----l^- 


\ 


I  "I    _  — 1      ^  I 


^\^-H-  ~{r 


fitAi.'V    ^/»'£-/y 


Ki.j.  L\r 


PLAN 

(Jon«^r.»l  nrransr«Miuut  t.f  lM»at  ^towapo  f«>r  a  small  coastipg  etea 


luaniior  \\\\\\  tliov  can  bo  (iiiiiklv  ami  oasilv  lot  down  to  the  wa 
lino.     This  provision  is  of  paitioular  importance  where  rafts 
buoyant  apparatus  aro  carrioil  on  boanl. 


ROUND   BAR  RADIAL  DAVITS  421 

It  has  been  suggested  that  it  would  be  an  advantage  in  large 
passenger  steamers  to  stow  the  boats  on  two  decks,  but  it  is 
considered  that  great  difficulty  would  result  in  the  confusion  of 
orders  given  to  the  boats'  crews,  and  there  would  be  great  risk 
of  the  upper  boats  being  launched  before  the  lower  ones  were 
clear  of  the  ship's  side. 

SECTION  B.— ROUND  BAR  RADIAL  DAVITS 

A  NUMBER  of  articles  have  been  jnitten  from  time  to  time  in 
marine  magazines  as  to  the  relative  value  of  ordinary  radial 
davits  compared  with  the  mechanical  davit,  crane,  or  other 
patent  launching  apparatus.  In  the  majority  of  cases  one  cannot 
fail  to  discover  that  these  descriptions  have  been  more  or  less 
inspired  by  the  particular  persons  financially  interested  in  the 
special  devices  designed  to  operate  the  launching  of  ships'  boats. 
Each  patentee  claims  to  have  solved  all  the  difficulties  associated 
with  this  much-debated  subject. 

There  are  sources  of  weakness  and  disadvantage  associated 
with  almost  every  design  of  launching  apparatus,  but  each  type 
possesses  some  distinctive  feature  which  appeals  to  the  individual 
and  finds  favour  with  the  shipbuilder  and  shipowner.  No 
particular  standard  gear  is  recognised  by  the  Board  of  Trade, 
and  provided  the  proposed  apparatus  fulfils  all  the  requirements 
of  the  regulations  and  successfully  stands  the  prescribed  tests, 
the  Board  of  Trade  give  every  assistance  for  that  device  to  be 
fitted  on  a  vessel  as  a  part  of  the  statutory  equipment. 

To  absolutely  condemn  the  principle  of  the  ordinary  round 
tar  radial  davit  is  not  justified  by  general  experience.  There 
are  certain  well  known  limitations  to  this  type  of  davit,  especially 
when  operating  the  large  number  of  boats  now  carried  on  passenger 
and  emigrant  ships.  Many  patent  devices  have  been  designed 
to  minimise  the  drawbacks  associated  with  the  ordinary  davit, 
but  owing  to  the  ease  with  which  the  latter  can  be  manufactured 
by  the  shipbuilder  on  his  own  premises,  and  the  relative  advantage 
in  cost  of  production  as  compared  with  patent  apparatus,  together 
with  the  seamen's  long  association  with  the  manipulation  of  this 
type  of  davit,  it  is  suggested  that  it  will  take  some  lengthy  period 
before  they  will  be  completely  replaced  on  ocean-going  cargo 
steamships. 

One  of  the  difficulties  which  is  always  associated  with 
the  operation  of  launching  the  boats  overboard,  is  that  during  the 
process  of  lowering,  the  boat  is  free  to  swing  transversely  with  the 


422  SHIPS'  BOATS 

risk  of  coming  violently  into  contact  with  the  ship's  side.  Many 
devices  have  been  suggested  on  various  occasions  to  lessen  the 
danger  to  the  occupants  of  the  boat.  The  fitting  of  ropes  or 
jackstays  to  the  ship's  side  for  guiding  the  boats  to  the  water- 
level,  is  considered  objectionable  and  dangerous,  especially 
when  the  vessel  is  rolling  heavily,  as  there  would  be  the  serious 
possibiUty  of  swamping  the  boat. 

In  any  case,  there  must  be  adequate  provision  made  for  keeping 
the  boats  close  to  the  ship's  side  from  the  time  the  lowering 
operation  is  commenced  until  Ae  boat  reaches  the  deck  or  position 
from  which  the  passengers  are  embarked. 

It  is  advisable  to  arrange  for  the  passengers  to  be  embarked 
on  the  lowest  open  deck.  The  boat  deck  should  only  be  available 
for  the  crew  who  are  operating  the  launching  apparatus.  The 
rush  of  passengers  into  tl^e  boats  and  interfering  with  the  gear, 
has  been  responsible  for  accidents  which  have  often  been  attri- 
buted to  the  inefficiency  of  the  crew  and  the  bad  condition  of 
boats  and  launching  gear. 

Freedom  for  operation  is  an  absolute  necessity  in  case  of  panic 
and  disaster. 

General  Rule  13  of  the  Rules  for  Life-saving  AppUances  of 
1914  stipulates  requirements  which  must  be  carried  out  in  equip- 
ping vessels  with  apparatus  for  launching  ships'  boats.  They  are 
as  follows  : — 

Appliuncesfor  lowering  Boats, 


(C 

cc 


a 


(1)  The  davits  shall  be  of  approved  form  and  fitted  on  one 
or  more  of  the  decks  in  such  positions  that  the  boats  can  b^ 
efficiently  lowered  from  tliem,  and  shall  be  so  spaced  and  placed 
"  that  the  boats  can  be  swimg  out  with  facihty.  Davits  shall 
not  be  fitted  in  the  bows  of  a  ship,  but  they  may  be  fitted  in 
any  other  position  in  the  ship,  provided  that  the  boats  are  not 
brouglit  into  dangerous  proximity  to  a  propeller  at  the  time  of 
''  launching. 

"  (2)  The  davits,  falls,  blocks,  and  all  other  gear  required 
**  for  lowering  the  boats,  shall  be  of  sufficient  strength  to  the 
'*  satisfaction  of  the  Board  of  Trade,  and  in  the  case  of  foreign- 
*  going  passenger  steamers  launched  on  or  after  the  1st  March, 
"  1913,  they  shall  be  such  that  the  boats  can  be  lowered  safely 
"  with  the  full  complement  of  persons  and  equipment,  the  ship 
"  being  assumed  to  have  a  list  of  15  degrees. 

(3)  In  the  case  of  foreign-going  passenger  steamers  launched 
on  or  after  the  1st  July,  1914,  the  davits  shall  be  fitted  with  a 


ROUND   BAR  RADIAL  DAVITS  423 


-  ELEVATION  — 


Fio  L'n><. — Oencial  a 


c-'JJr.. 

— V-f 

'" 

Tli^:«?« 

":3:. 

: 

J:!::--,- 

::%:, 

X 

'''"m 

■::i==^ 

.'r'       /*?-" 

/> 

\ 

^ 

/r       / 

"'."/. 

,..«., 

■ 

^,^ 

^r-7 

J^*^^ 

•--•_3^ 

-4*^ 

_ 

,J_;^tf^*^              0"—"f-«' 

imctaa 

«™™  «roMr,rs 

i-a- 

-   P  I-  ft  N  — 

of  boot  stowage  for  a  24-ft.  Ctaaa  Ia  lifeboftt. 


424  SHIPS'  BOATS 


(i 


gear  of  sufficient  power  to  ensure  that  the  boat  can  be  turned 
out  against  the  maximum  list  under  which  the  lowering  of  the 
"  boats  is  possible  on  the  vessel  on  which  they  are  fitted. 

"  (4)  The  boat's  falls  shall  be  long  enough  to  lower  the  boat 
"  into  the  water  with  safety  when  the  vessel  is  light.  Life-lines 
'*  shall  be  fitted  to  the  davit  spans,  and  shall  be  long  enough  to 
"  reach  the  water  when  the  vessel  is  light.  Hooks  shall  not  be 
"  attached  to  the  lower  tackle  blocks. 

(5)  Means  shall  be  provided  for  speedily,  but  not  necessarily 
simultaneously  or  automatically,  detaching  the  boats  from  the 

''  falls  ;  the  boats  placed  under  davits  shall  be  attached  to  the 
"  falls  and  kept  ready  for  service ;  the  points  of  attachment 
of  the  boats  to  the  falls  shall  be  sufficiently  away  from  the  ends 
of  the  boats  to  ensure  their  being  easily  swimg  clear  of  the 
davits ;  the  boats'  chocks  shall  be  of  such  construction  and 
arrangement  as  shall  be  satisfactory  to  the  Board  of  Trade. 

(6)  Where  more  boats  than  one  are  served  by  the  same  set 
of  davits,  there  shall  be  provided  an  approved  appUance  for 
lowering  the  boats  in  turn  and  rapidly,  and  arrangements  ahsAl 
be  made  to  prevent  the  falls  fouling  when  they  are  recovered. 

(7)  The  Board  of  Trade  may  accept  in  Ueu  of  davits  or  sets 
of  davits  any  other  appliance,  appliances,  or  arrangements, 
whicli  appear  to  them  at  least  as  effective  as  davits  for  placing 
the  boats  in  the  water." 


(( 
(< 
(( 

i( 
(( 
(( 
(< 

<< 
(i 
<( 
(( 


For  the  ordinary  radial  davits  to  be  effective  and  serve  the 
purpose  for  which  they  are  intended,  they  must  be  fitted  on  the 
vessel  with  care  and  forethought  as  to  the  actual  requirements. 
The  davits  should  be  placed  at  such  a  distance  apart  as  will  allow 
the  boat  to  swing  out  smoothly  and  easily,  with  the  falls  always 
hanging  plumb. 

The  relative  positions  of  the  head  of  the  davit  and  the  collars 
or  deck  sockets  can  be  easily  fixed  in  the  drawing  office  with 
the  aid  of  paper  moulds.  It  frequently  occurs  when  inspecting 
the  life-saving  appUances  of  a  new  ship  to  find  that  the  boat  has 
to  be  lifted  at  certain  positions  when  swinging  out  the  davits, 
in  addition  to  being  pushed  out,  in  order  to  reach  the  outboard 
position.  A  httle  preparatory  work  in  the  office  would  have 
obviated  the  difficulty. 

A  typical  boat  stowage  arrangement  is  given  in  Figs.  288  and  240. 
The  length  of  the  boat  is  24  ft.,  the  distance  between  the  davit 
centres  is  21  ft.,  and  that  between  the  davit  heads  is  18  ft.  9  in. 
The  position  of  the  hfting  hooks  would  therefore  be  2  ft.  7J  in. 


ROUND  BAR  RADIAL  DAVITS 


from  the  intersection  of  the  outside  of  the  planking  with  the 
stem,  Btempost,  or  after  edge  of  transom,  as  the  case  may  he. 


Fio.  239. — Bound  bar  radial  davits  for  »  24-f(.  Class  1^  lifobont. 


A  common  practice  is  to  weld  a  thumb  cleat  on  the  davit  to 
take  the  load  of  the  fall  from  the  upper  block  and  allow  the  boat  to 


4S0 


SHIPS*  BOATS 


swing  clear  of  the  falls  when  launching  outboard.     It  is  geneiaD]^ 
coiuidered  that  this  fitting  is  daogeroas  and  should  be  condemned. 

The  boat  cannot  be  Tsised  from  the  chocks  with  the  fall 
nimung  over  the  cleat,  consequently  when  the  former  is  lifted 
clear  it  becomes  neceasaiy  to  temporarily  laah  the  falls  between 
tlie  two  blocks,  to  allow  the  lead  to  be  replaced  over  the  thumb 
cleat  and  carried  down  to  the  belaying  cleat,  bollard,  or  snatch 
block. 

The  clump  block  fitted  at  the  throat  of  the  davit  acting  in 
conjunction  with  a  snatch  block  at  the  heel,  or  a  combiued 
bollard  and  sheave  as  illustrated  in  Figs.  '24U  and  '241,  is  a  more 
serviceable  and  satisfactoTy  arrangement. 

Single  wire  guy  ropes  are  usually  fitted  to  the  davits  on  cargo 
vessels,  but  the  practice  is  not  recommended  and  should  be 
replaced  by  gun-tackle  purchases,  as  being  a  more  reliable 
method  of  controUing  the  da^-ita  when  launching  the  boats  into 
the  outboard  position. 

At  least  four  life-lines  should  be  seized  to  the  span  between 
the  heads  of  the  davits  on  all  passenger  vessels ;  the  length  of 
the  linos  must  be  sufficient  to  reach  the  hgbt  water-line. 

It  is  very  essential  that  particular  care  be  taken  to  have  t 
hole  in  the  head  of  the  davit,  which  takes  the  swivel  bolt  of  t 
upper  block,  in  a  true  vertical  plane.  The  operation  is  usual 
undertaken  when  the  davit  is  being  forged  on  the  slab  in  \ 
shipyard.  The  slightest  amoimt  out  of  the  vertical  will  cam 
friction  and  prevent  the  boat  swinging  out  easily. 

The  securing  nut  to  the  swivel  bolt  must  be  recessed,  as  ahowi 
in  Fig.  239,  to  enable  a  proper  bearing  being  taken  on  the  davj 
and  not  on  the  spectacle  which  is  connected  to  the  spar  and  g 
ropes.  Attention  should  always  be  given  to  these  fittings  to  a 
that  they  work  smoothly  and  do  not  jamb. 

The  socket-davit  has  long  been  considered  out  of  date  a 
ine£Gcient.     Yet  its  vae  is  often  permitted,  and  the  combinstioi 
fitted  as  a  part  of  the  statutory  equipment  of  out  i 
vessels. 

There  is  one  serious  limitation  to  the  radial  davit,  under  1i 
present  requirements  of   the  Kules  for  Life-saving  Appliai 
It  is  unable  to  launch  a  boat  over  the  ship's  side  against  a  li 
imless  it  is  operated  with  a  mechanical  turning  out  or  sluing  geaS 

The  British  regulations  do  not  insist  on  a  mechanically-operate 
davit  being  fitted  to  the  ordinary  cargo  vessel,  because  suffida 
soaring  accommodation  is  provided  in  the  boats,  on  either  side  Q 
the  vessel,  for  the  total  number  of  persons  on  board. 


ROUND  BAR  RADIAL  DAVITS 


427 


In  a  f oreign'-gomg  p'assenger  vessel,  i.e.  a  vessel  canying  fnore 
than  twelve  passengers,  the  davits  must  be  designed  to  allow  the 
boats  to  be  launched  under  the  condition  when  the  vessel  is 


titS^€crAct£  pukre. 


9'DfM:  OUAOROPLE SHCA^eO 

)rttWT.  Iron  Block 


S/s  MACULA  FALLS 


B'0/Arff£BL£  SH£A¥£D 

3lo€m 


Fiu.  240. — Round  bar  radial  davits  for  a  28-ft.  Class  Ia  lifeboat. 


assumed  to  have  a  list  of  15  degrees,  the  boat  being  loaded  with 
the  full  number  of  persons  and  details  of  equipment. 

lllustratioAs  of^a  mechanical  apparatus  designed  for  operating 


428 


SHIPS'  BOATS 


ordinary  radial  davits  against  a  heavy  list,  are  ^ven  in  . 
2-21  and  '241.  The  latter  shows  (he  details  of  the  worm 
and  screw  gear  attached  to  the  davit  at  the  deck  level.  This 
mechaniam  ia  the  invention  of  Mr.  Georj-e  Tumbull,  M.I.N. A., 
of  the  firm  of  Me.'wrs.  Alfred  Holt  &  Co.,  Ltd.,  and  has  been  fitted 
to  quite  a  number  of  passenger  vessels  now  in  service.  The  saine 
type  of  gear  can  be  fitted  to  socket-davits,  where  the  boat  i 
launched  over  stanchions  and  fixed  guard  rails  at  the  ship's  sid] 
Such  an  arrangement  is  illustrated  in  Fig,  242. 


Several  other  gears  have  been  approved  by  the  Board  i 
Trade  and  adopted  by  a  number  of  shipowners. 

The  Pett's  Patent  Davit  Tuming-out  Grear  is  controlled  by  d)1^ 
Quixo  Davit  Co,  of  Ixandon,  and  is  very  similar  in  principle  t 
the    Tumbull    patent.     The    Peninsular    and    Oriental    Ste 
Navigation  Company  has  recently  installed  one  of  their  late 
passenger  vesseb  with  the  Quixo  Davit  Co.  s  apparatus. 

The  Welin  Davit  and  Engineering  Co.  have  patented  i 
arrangement  which  is  operated  by  a  wire  rope  control,  called  t 
"planet  system,"  and  is  designed  expressly  for  mampu) 


ROUND  BAR  RADIAL  DAVITS 


429 


ordinary  round  bar  davits  and  turning  them  outboard  against 
a  vessel's  list. 

It  is  false  economy  to  nip  down  the  overhang  of  the  davit 
to  the  lowest  limits  in  order  to  save  weight  of  material  and  cheaper 
production.  When  the  boat  is  launched  overboard  there  must 
be  at  least  12  inrhea  clearance  fit  thi-  Iil'Iu  w;itcr-line,  between 


Fio-  243,— Turnljiill' 


t^e    boat   and   the   ship's  side,  the  vessel  being  In  an  uprij^hl 
position.     The  height  of  the  head  of  the  davit  above  th' 
support  of  ihe  boat  deck,  should  be  such  that  when  the 
is  stowed  in  the  chocks,  there  will  be  a  distance  of  at  ]f 
blocks  between  the  lower  and  upper  fall  blof^l        ' 
should  allow  the  boat  to  be  raised  clear  c' 
becomes  impossible  to  hinge  the  latter  do 


430 


SHIPS'  BOATS 


Particular  attention  must  be  given  to  the  method  of  securing 
the  collars  and  heel  sockets,  sufficient  riveting  being  arranged 
to  maintain  an  efficient  connection  to  the  hull  of  the 'vessel, 
especially  in  view  of  the  stress  exerted  on  the  davit  when  the 
vessel  is  rolling  heavily  in  a  seaway. 


TABLE   XXX. 
Approximate  Weight  and  Strength  of  Standard  Quality  Manila  Ropk.* 


Dlam. 

Diam. 

Clr. 

1 

Clr. 

Approx.  length 

of  manlla  rope 

in  lib. 

Approx.  weight 
and  length  of  ooil. 

Approx. 

3.S. 
borne  by 

Ins. 

mm. 

Ins. 

mm. 

i 

maaUa 

1 

1     ' 

12-7 

Ft. 

m 

In. 

Lbs. 
35 

Ft. 

1 

rope. 

lG. 

i"< 

4-8 

i 

1 
2100     , 

550 

i 

«>-3 

i 

19 

66 

50 

2750 

620 

A 

8 

1 

25-4 

41 

55 

2250 

1,000 

i 

10 

U 

28-5 

27 

■ 

60 

1620 

1,276 

■i 

11        i 

ij 

32 

IS 

70 

1260 

1,875 

12-7    1 

li 

38 

13 

4 

90 

1200 

2,400 

1 

1**       i 

n 

44-4 

9 

7 

126 

1200 

3,300 

16       i 

2 

50-8 

7 

() 

160 

1200 

4,000 

2 

19 

h 

57 

6 

1 

198 

1200 

4,700 

H 

2or» 

n 

03-5 

r> 

1 

234 

120(h 

5.600 

1 
H 

22 

'11 

70 

4 

5 

270 

1200 

6,600 

1 

25-4    1 

3 

76 

3 

8 

324 

1200 

7,500 

W^ 

27 

H 

82-5 

3 

2 

378 

1200 

8,900 

»i 

28-5 

3J 

88-9 

2 

9 

432 

1200 

10,500 

n 

:u-7 

n 

95 

2 

5 

504 

1200 

12,500 

^h 

33 

4 

101-6 

2 

1 

576 

1200 

14.000 

n 

35 

H 

lUS 

1 

10 

()48 

1200 

15.400 

n 

38 

4.V 

114 

1 

8 

720 

i200 

17,000 

1  K 

390 

4] 

120-6 

1 

6 

810 

1200 

18,400 

41 

5 

127 

1 

4 

900 

1200 

20,000 

n 

44 

5^ 

140 

1 

1        1 

1080 

1200 

25,000 

•> 

50-8 

() 

l.'>2 

-  - 

i      11 

1296 

1200 

30,000 

-){ 

oi 

1 65 

— 

,    n 

1512 

1200 

33,iH)0 

57 

7 

17S 

— 

;   8 

1764 

1200 

37,000 

n 

<)3-5 

'h 

190-5 

7 

2016 

i200 

43,000 

(W)-7 

8 

203 

— 

'       H 

2304 

1200 

50,000 

u 

73 

H\ 

216 

-- 

\       ^^ 

2590 

1200 

56,000 

:i 

7t> 

\) 

228-6 

— 

^ 

2915 

1200 

62,000 

3i 

79 

9.1 

241 

- 

'    H 

3240 

1200 

68,000 

31 

H2-5 

lo" 

2.">4 

-— 

4 

3600 

1200 

75,000 

The  weight  and  strengtli  of  manila  rope  per  table,  is  approximate  and  may 
vary  slightly  either  waj.  Manila  and  sisal  standard  rope  will  weigh  about 
alike.  Jn  the  lower  grades  of  manila  and  sisal  there  are  greater  variations  in 
weight  and  strength,  according  to  quality.  Four  (4)  strand  rope  weighs  from 
5  per  cent,  to  7  per  cent.  heavi(T  than  three  (3)  strand  plain  laid  rope.  Manila 
rope  runs  approximately  25  per  cent,  stronger  than  sisal. 


Supplied  by  the  Waterbury  Company,  New  York. 


ROUND  BAR  RADIAL  DAVITS  431 

The  emergency  lifeboats  are  carried  outboard  and  near  the 
bridge,  during  the  whole  of  the  voyage  at  sea,  and  maintained  in 
a  position  of  security  by  fitting  pudding  fenders  attached  to  the 
davits  (See  Figs.  238  and  '240),  die  boat  being  hauled  close  in  to 
the  fenders  by  canvas  griping  bands,  Ordinary  rope  lashings 
are  not  recommended  in  place  of  the  griping  bands,  as  the  continual 
rolling  of  the  ship  produces  too  much  friction  between  the  rope 
and  boat  planking,  with  detrimental  eSect  to  the  latter. 

In  arranging  the  size  and  pattern  of  blocks,  due  regard  should 
be  paid  to  the  standard  of  strength,  or  factor  of  safety,  recognised 
by  the  Board  of  Trade  in  connection  with  details  of  davit 
equipment. 

It  JB  anticipated  that  regulations  will  soon  be  in  operation 
whereby  detailed  information  will  become  available  for  the  use 
of  the  shipbuilder  to  fix  the  sizes  of  the  blocks  and  associated 
fittings. 

The  writer  has  often  heard  complainta  from  ships'  officers 
as  to  the  unreliability  of  tarred  hemp  for  davit  falls.  The  action 
of  the  weather  is  often  rLwpcjnsible  for  the  sudden  collapse  of  the 
falls  without  giving  pre\'iou3  warning  or  any  visible  indication 
of  weakness. 

The  working  load  of  manila  rope  is  usually  about  one-fifth 
of  the  breaking  stress.  All  blocks  should  be  fitted  with  patent 
roller  sheaves.  Manila  is  stronger  than  tarred  hemp.  Ordinary 
hemp  rope,  unless  it  is  tarred,  quickly  deteriorates  when  exposed 
to  the  weather;  the  effect  of  tarring,  however,  reduces  its 
strength. 

Manila  hemp  is  obtained  from  a  species  of  wild  plantain  be- 
longing to  the  banana  family,  and  grows  in  the  Philippine  Islands. 
The  fibre  is  silky  and  lustrous  in  appearance  and  very  tenacious, 
but  light  in  weight.  The  strength  and  weight  of  manila  rope  is 
shown  in  Table  XXX. 

The  usual  practice  is  to  fit  wooden  blocks  when  serving 
manila  falls,  and  iron  blocks  for  wire  rope.  General  experience 
has  proved  it  an  advantage  to  have  iron  non-toppling  blocks 
instead  of  blocks  made  of  wood,  for  the  weight  of  the  former 
assists  the  block  in  preventing  it  from  turning  over  when  recover- 
ing the  falls. 

Special  patient  roller  sheaves  are  very  r  d  it  is  an 

added  advantage  to  bush  the  sheave  pin?  ion. 

The  becket  is  secured  to  tb*  ck,  the 

purpose  of  which  is  to  liok  imble 

attached  to  the  standing  j  uper 


432 


SHIPS'  BOATS 


block  is  fitted  with  treble  sheaves,  and  the  lower  block  with 
double  sheaves,  then  the  becket  is  fitted  on  the  lower  block,  but 
when  the  upper  and  lower  blocks  are  fitted  with  the  same  nambei 
of  sheaves,  then  the  becket  is  fitted  on  the  upper  block. 


TABLE  XXXI. 
FiBBE-CLAD  Wire  Hoisttno  Rope,  Cruotblk  Cast  Btkel. 
Composed  of  five  strands  and  a  hemp  centre.     Nineteen  wires  to  the  stimnd 


IMamet^r 

in  Inches 

before 

»erviDg. 


Approx. 

diameter 

after 

serving  with 

marUne. 


Appro  X. 
circumfer- 
ence aft€r 
serving  with 

marline. 


Approx. 

breaking 
load  m 
tons  of 

2000  lbs. 


Allowable 

working 

load  in 

tons  of 

2000  lbs. 


Minimum 

sixeof  drum 

or  sheave 

in  feet. 


Approx 


per  foot 
inlbe. 


1 

I 
If, 

•♦ 
<* 

M 

I 

7 
H 

I 

u 


9 

10 


4 


u 
111 


I.', 

1.' 

12 


u 

2 

21 

9  3 

*'H 

:u 

•J  7 

5A 

.'->; 


2-2 
3  1 

4-8 
«-5 
8-4 

100 

12-5 

17-5 

23 

30 

38 

47 

5(> 

04 

72 

85 


0-44 
0-62 
0-96 
1-30 
1-68 
200 
2-50 
3T)0 
4H0 
HOO 
7(>0 
9-4 

11(> 

12-8 

14-4 

170 


i 

1 

U 

H 

n 
^ 

3 

3J 

4 

—   5 
5i 
5} 

7i 


•21 

•26 
•36 
•40 
•49 
60 
•80 
112 
1-29 

1  -mi 

2-07 
2^52 
3  06 
3-60 
419 
4-88 


Before  reeving  the  falls  tliey  sliould  be  carefully  stretched  ; 
and  after  reeving,  tlie  shackle  attached  to  the  becket  should 
be  dis(;(»nnected  and  the  turns  taken  out  of  the  falls  before 
re])lacing. 

Tiie  Board  of  Trade  have  issued  instructions  to  the  effect, 
that  in  order  to  provide  for  speedily  detaching  the  falls  by  hand 
when  tlie  boat  is  waterbome,  all  lower  fall  blocks  are  to  be  fitted 
with  a  suitable  ring  or  long  link  for  attachment  to  the  sUng 
hooks  fitted  in  the  boat,  unless  some  approved  form  of  disen- 
gaging gear  is  adopted.  Tlie  eye  on  the  block  and  the  ring  or 
link  ar(»  to  be  sucli  as  to  provide  a  factor  of  safety  of  at  least 
four,  with  a  dead  working  load  equivalent  to  the  total  weight  of 
boat,  e(|uipnient,  and  full  complement  of  persons. 

The  following  extract  has  been  suppUed  by  the  Waterbury 
Company  of  New  York,  Chicago,  etc. 


ROUND  BAR  RADIAL  DAVITS  433 

Notes  on  Use  and  Care  of  Rope. 

Deterioration  in  rope  is  both  mechanical  and  chemical :  first, 
due  to  surface  wear  or  from  friction  between  fibres ;  secondly, 
from  exposure  to  weather  and  acids.  Surface  wear  on  ropes 
hkewise  follows  wtere  worked  through  blocks  or  where  sheave 
holes  are  too  small  for  easy  clearance  or  where  blocks  become 
fouled,  causing  improper  alignment,  the  result  of  which  is  chafing 
of  the  rope. 

Ropes  swell  to  some  extent  after  being  wet.  Blocks  with 
large  enough  sheave  grooves  should  be  used  to  take  care  of  swell. 
Unlike  metal  and  other  similar  substances,  fibre  rope  has  not  a 
permanent  elastic  limit  in  which  it  may  be  worked  indefinitely 
without  injury.  Owing  to  the  tendency  of  the  fibres  to  slip  one 
upon  another,  the  rope  gradually  loses  its  cohesion  imder  the 
repetition  of  very  moderate  tension,  and  may  be  seriously  weakened 
by  constantly  working.  If  fibre  rope  is  subjected  to  a  sudden 
stress  or  even  to  a  stress  approaching  that  of  breaking,  its 
strengtli  is  permanently  reduced,  and  it  may  be  expected  to  give 
way  under  a  ver\'  moderate  pull.  Hence  it  is  advisable  to  allow 
for  liberal  factors  of  safety,  both  as  to  working  and  breaking 
strains. 

Internal  friction  between  the  fibres  increases  to  some  extent 
when  the  rope  is  worked  over  a  sheave.  This  ultimately  has  a 
tendency  to  break  up  the  fibres,  which  also  suffer  a  loss  of  vitality 
through  heat  caused  by  friction.  The  smaller  the  diameter  of 
sheave  in  this  connection  the  greater  the  friction.  The  use  of 
sheaves  of  the  largest  diameter  permissible  is  advisable,  likewise 
rope,  as  the  ultimate  results  will  justify. 

AU  rope  should  be  kept  clean  and  free  from  sand,  mud,  or  other 
matter  containing  grit.  Chemical  deterioration  from  rotting,  or 
termed  by  some  "  dry  rot,"  generally  increases  through  rope 
becoming  water-logged  and  not  given  an  opportunity  to  dry 
out  in  the  open  air.  Allow  the  rope  to  dry  naturally.  Do  not 
cover  or  prevent  drainage  as  it  retards  the  drying  out  process. 

When  dragging  rope  over  the  ground  it  weakens  the  roi^^ 
and  dirt  and  grit  are  picked  up  which  grind  in  when  the  if 
used  again.  Unnecessary  surface  wear  often  occurs  with  ho 
machinery  by  contact  against  iron  beams  or  the  edges  of  i 
blocks.  In  transmission  the  surface  friction  rope  agaiiu 
sheave  also  wears  it,  but  the  wear  is  ina  "^n 

with  that  of  a  poor  installation. 

Be  careful  in  storing  your  rope 


434  SHIPS'  BOATS 

commercial  acids,  which  have  a  particularly  injurious  effect  oi 

the  fibre. 

Always  use  the  largest  rope  permissible,  as  the  limit  of  safety  oi 
small  rope  is  reached  quickly.  Inspect  ropes  frequently  anc 
replace  before  the  Umit  of  ssiety  is  reached.  Loss  of  strengtl 
from  heat  or  rotting  is  difficult  to  note  except  following  test  o: 
fibre.  Internal  wear  can  only  be  judged  after  careful  inspection 
Large  ropes  do  lose  strength  through  rotting  as  quickly  as  th< 
small  ones. 

Extreme  tension  occurs  frequently  in  slings  bending  ovei 
sharp  comers  while  under  load.  This  breaks  the  fibres  on  the 
outer  side  while  the  sharp  comers  cut  the  ones  on  the  inner  side. 
To  secure  the  best  service  from  slings,  sharp  bends  over  un}'ieldino 
surfaces  must  be  avoided  and  the  load"  should  be  considerablv 
less  than  the  tensile  strength  of  the  rope. 

Running  rope  should  never  be  allowed  to  touch  anything  but 
the  wheels  or  sheaves  upon  which  it  works,  neither  should  the 
rope  chafe  against  the  side  of  grooves  of  the  wheels.  Avoid 
vibration  and  slipping  of  ropes  as  far  as  possible. 

Be  careful  to  have  sheaves  accurately  balanced  and  in  perfect 
ahgnment,  otherwise  rope  is  liable  to  jerk,  chafe,  and  destroy  itself. 

Manila,  when  dry,  contains  a  small  percentage  of  moisture, 
but  will  absorb  as  much  as  30  to  40  per  cent,  in  a  damp  atmosphere. 
Moisture  does  not  tend  to  promote  decay.  In  hot,  dry  weather, 
an  occasional  wetting  of  the  rope  will  aid  it.  A  freezing  temper- 
ature renders  the  fibres  brittle. 

Four-strand  rope  will  weigii  from  5  to  7  per  cent,  heavier  than 
3 -strand  rope  of  medium  lay. 

Kope  is  laiowii  as  right  lay  or  left  lay.  In  left-lay  rope  all 
turns  are  reversed  from  those  of  the  ordinary  right-lay  rope, 
the  yam  being  s})un  to  the  left. 

Twisting  of  hoisting  rope  may  be  lessened  by  soaking  rope 
in  water,  then  allowing  it  to  diy  out  thoroughly. 

A  common  factor  for  hoisting  load  is  5  to  1  or  one-fifth  of  the 
breaking  strain. 

Small  sheaves  waste  power  and  increase  wear  on  ropes. 

Rope  is  weakened  in  a  sliarp  nip  of  any  kind,  whether  due  to 
a  sphee,  a  bad  lead,  a  hitch  or  a  bend  around  a  pin  or  a  post, 
due  to  tensi(m  upon  the  layers  of  fibre  from  the  inside  to  outside 
bend,  the  outer  layers  being  subjected  to  tension,  while  the 
inner  layers  are  compressed.  As  a  result,  the  outer  layers  wear, 
followed  by  othei*s  in  succession  toward  the  inside. 


■  ROUND    BAR    RADIAL   DAVITS  435 

Waterbury  fibre-cUd  wire  rope  ia  bein^  extensively  used  by 
the  United  States  Bhipbuiidera,  It  is  a  wire  rope,  each  atrand 
of  which  ia  served  with  the  best  grade  of  tarred  Russian  hemp 
marline.  Tliis  fibre  covering  prevents  the  chafing  and  wear 
of  the  wire  strands  during  flexing  movements,  and  after  being 
in  service  a  short  time  this  fibre  covering  packa  into  the  inter- 
stices of  the  strands,  resulting  in  a  rope  having  a  smooth  cyhndrical 
surface.  It  is  unaffected  with  the  changes  in  atmospheric 
conditions,  and  is  therefore  well  adapted  for  the  purpose  of  davit 
falls.  Fibre-clad  is  about  one-third  the  diameter  of  m&nila  rope 
of  the  same  strength.     (See  Table  XXXI.  on  p.  432.) 

Galvanised  rope  should  never  be  used  for  running  rope,  as 
the  zinc  quickly  wears  off  and  rust  sets  in  with  great  rapidity, 
A  good  preservative  is  a  mixture  of  crude  petroleum  and  graphite. 

Wear  increases  with  the  speed ;  it  is,  therefore,  very  essential 
that  single  wire  falls  should  receive  constant  attention. 

Sheaves  should  be  scored  to  the  diameter  of  rope  and  particular 
care  taken  to  see  that  there  is  no  chafing  the  sides  of  the  grooves. 

PRACTICAL   RULES    FOR   ROPES,    BLOCKS    AND    TACKLE.'* 

1.  To  find  the  safe  working  load  of  a  luanila  rope  of  given 
aiee,  square  the  circumference  in  inche-s  and  divide  by  7  for  the 
load  in  tons. 

2.  To  find  the  size  of  a  rope  for  a  given  working  load,  multiply 
the  load  in  tons  by  7  and  take  the  square  root  of  the  product  for 
the  circumference  of  the  rope  in  inches. 

3.  To  find  the  size  of  a  rope  when  rove  as  a  tackle  to  lift  a 
given  weight,  add  to  the  weight  one-tenth  of  its  value  for  every 
sheave  to  be  used  in  hoistmg.  This  gives  the  total  resistance 
including  friction  :  divide  this  by  the  number  of  parts  at  the 
movable  block  for  the  maximum  tension  on  the  fall.  Reeve  "the 
fall  of  a  sjze  to  stand  this  tension  as  a  safe  working  load. 

EmmfU. — To  lift  10  tons  with  a  three-fold  purchase,  the  fall 
of  which,  coming  from  the  upper  block,  is  taken  through  an 
extra  sheave  on  deck  for  a  fair  lead.  Required  :  the  size  of  the 
fall. 

Total  resistance,  including  friction,  equals 

I  10  +  7  X  jiJ=fiaHV 

Maximum  tension  on  falls  equals  '^  "^^^^^^^ 
Size  of  fall,  not«  2.  equals  V?  X  2'^^^^^^H|^^_^ 
: 


436  SHIPS'  BOATS 

• 

4.  To  find  the  weight  which  a  given  purchase  will  lift  with 
safety,  find  the  safe  working  load  for  the  rope  to  be  used.  Note 
1,  multiply  this  by  the  number  of  parts  at  the  movable  block. 
This  gives  the  total  resistance  including  friction.  Multiply  the 
total  resistance  by  10  and  divide  by  10  plus  the  number  of 
sheaves  used.     The  result  is  the  weight  that  may  be  lifted. 

Eaumple, — ^To  find  the  weight  which  may  be  lifted  by  a  fall 
of  4J-in.  manila  rope  as  a  three-fold  purchase,  the  fall  of  which 
leads  from  thef upper  block  through  an  extra  leader  on  deck  : — 

4*52 
Safe  working  load  — -  =  2*9  tons 

Total  resistance,  bicluding  friction,  6  X  2*9  =  17'4  tons 

17*4  X  10       174 
Weight  to  be  Ufted     ^r^^r,    ^  lY  ~  ^^'^  tons. 


The  decisions  arrived  at  by  the  International  Convention 
for  Safety  of  life  at  Sea,  liave  now  been  practically  embodied  in 
all  the  regulations  issued  by  the  Board  of  Trade. 

The  standard  weight  for  each  adult  person  is  estimated 
at  1G5  lbs.,  and  the  strength  of  davits,  boats,  and  all  associated 
equipment  is  based  on  this  standard  in  Great  Britain.  • 

The  davits  fitted  to  foreign-going  passenger  vessels  must  be 
of  suflicient  strength  to  safely  lower  the  boats  into  the  water, 
fully  equipped,  and  to  carry  the  maximum  number  of  persons 
for  which  they  are  allowed. 

The  differeuce  between  140  lbs.  the  old  standard  of  weight 
per  person,  and  165  lbs.  the  present  standard,  makes  a  considerable 
difference  in  the  ultimate  test  load  to  be  placed  on  a  large  Ufeboat. 

To  provide  a  basis  upon  which  to  construct  a  formula  for 
obtaining  the  size  of  a  radial  davit  of  circular  section,  without 
the  necessity  of  resorting  to  intricate  calculation,  a  lifeboat  of 
Class  Ia,  28  ft.  in  length,  complete  with  equipment,  blocks,  falls, 
and  carr}'ing  50  persons,  is  taken  as  imposing  a  load  of  100  cwts. 
on  the  davits,  or  2  cwts.  per  person  for  which  the  boat  measures. 
This  is  briefly  stated  as  follows  : — 

W 

where  W  —  Total  load  on  davits  in  cwts. 

X  ~  Maximum  number  of   persons  for  which    the   boat 

measures. 
w  =  Load  on  davits  in  cwt-s.  per  pei-son  carried. 


ROUND   BAR  RADIAL   DAVITS  437 

Take  a  lifeboat  of  Class  Ia  with  the  following  standard  of 
dimensions :  28*0'  X  8*5'  X  3*5',  which  gives  an  actual  total 
capacity  of  833  cub.  ft.,  with  accommodation  for  50  persons. 

Then  |§^  =3  -12  cwt.  per  cub.  ft.  of  capacity 

or  \^^l^-  =3  2  CWts.  per  person. 

From  Table  XXVII.  the  weight  of  this  particular  size  of  boat 
is  given  as  119  cwts.  (say  120  cwts.). 

Then  Jjf  1^  =  14  cwt.  per  cub.  ft.  of  capacity 

or  ^^  =  2*4  cwts.  per  person. 

The  formula  which  enables  the  shipbuilder  to  readily  ascertain 
the  correct  diameter  of  davits  of  soUd  round  section,  and  approved 
by  the  Board  of  Trade,  is  as  follows  :— 


rf=^ 


L  X  B  X  D(H  +  4S) 
C~ 


where  L  =  Length  of  boat,  in  feet. 
B  —  Breadth  of  boat,  in  feet. 
D    =  Depth  of  boat,  in  feet. 
H  —  Height  of  davit,  in  feet,  above  upper  support.     (From 

upper  surface  of  collar  to  centre  of  crosshead.) 
8   ^  Span  of  davit,  in  feet.     (From  centre  of  davit  to  centre 

of  crosshead.) 
C  =1  Constant,  to  be  taken  as  86  for  iron  davits,  104  for 

soUd  ingot  steel  davits  of  from  27  to  32  tons  tensile 

strength,  and  for  hollow  welded  davits  of  from  26 

to  30  tons  tensile  strength. 
d  =  Diameter,  in  inches,  of  solid  davit. 

The  dimensions  L  X  B  X  D  are  those  which  are  ordinarily 
used  in  obtaining  the  correct  capacity  of  a  boat  for  appropriating 
the  number  of  persons,  as  described  in  Section  C  of  Part  II., 
and  illustrated  in  Fig.  23. 

The  foregoing  rule  is  only  applicable  when  the  weight  per 
*    person  does  not  exceed  2  cwts. 

Boats  vary  in  weight,  and  the  details  given  in  Table  XXVII. 
will  be  of  assistance  in  estimating  the  total  dead  load  on  the  davit. 

A  modification  to  the  constant  C  will  therefore  become 
necessary  in  the  majority  of  cases,  in  view  of  the  increased 
standard  weight  of  one  person  from  140  to  165  lbs.,  and  the 
increase  in  weight  in  the  majority  of  boats  due  to  maintaining  a 
minimum  scheme  of  scantUngs. 


438  SHIPS'  BOATS 

The  difference  in  weight  of  steel  and  wooden  boats  is  now 
practically  negligible. 

For  the  purpose  of  illustration,  let  us  take  four  separate  cases, 
and  apply  the  formula  approved  by  the  Board  of  Trade  for 
securing  the  correct  diameter  of  the  davit. 

(a)  Assume  that  the  davits  shown  in  Fig.  239,  are  of  wrought 
iron  and  fitted  on  a  passenger  steamer  where  the  full  load  has  to 
be  lowered  into  the  water. 

Formula  is — 


d  =  ^'LxBxD(H  +  4S)^^ 


C 

.      L  ==  240',  B  =  7-5',  D  =  30',  H  =.  100',  S  =^  575'. 

The  constant  C  is  86  for  iron  davits  when  the  weight.per  person 
does  not  exceed  2  cwts.  If  reference  is  made  to  Table  XXVII., 
we  find  that  the  total  weight  of  the  boat,  equipment,  number  of 
persons,  blocks,  etc.,  is  77*6  cwts.  (say  78  cwts.),  and  the  number 
of  persons  allocated  is  32.  Then  the  weight  per  person  is  5§  =2'44 
cwts.  The  constant  C  (86)  will  therefore  need  modification, 
and  the  correction  is  made  thus  : — 

86  X  2 
2-44     ^ 

The  formula  will  now  be — 


^  ^    y24-0  X  7-5  30  (100  +  230) 
V  71'  ' 


^  ^    7^40  X  33 
V        71 


d^sy 


17820 
71 

d  =  \/250 

d  =  6-3  in.  =^  (j}.^" 

d  =  say  6  {\.  in. 

The  relative  streiijujth  along  the  tapered  parts  of  the  davit 
must  be  fully  maintained. 

(6)  For  the  second  case,  let  us  take  the  same  particulars  for 
the  dimensions  of  boat,  etc.,  as  were  used  in  example  (a),  the  only 
difference  bein*^^  that  the  davits  are  to  be  fitted  on  a  cargo  vessel. 
It  has  been  j^^enerally  considered  that  such  a  davit  need  only  be 
strong  enough  to  carry  the  boat,  equipment,  and  a  sufficient 


ROUND   BAR   RADIAL   DAVITS 


439 


number  of  men  to  safely  handle  the  boat  during  the  ^process  of 
lowering.  No  objection  is  raised  if  the  diameter  of  thje  davit  is 
not  less  than  that  found  by  the  Board  of  Trade  formula^  but 
using  144  for  the  constant  C.  The  davits  are  of  untei^ted 
material.     The  procedur